(function(){if (!Date.now) Date.now = function() {
    return +new Date;
  };
  try {
    document.createElement("div").style.setProperty("opacity", 0, "");
  } catch (error) {
    var d3_style_prototype = CSSStyleDeclaration.prototype,
        d3_style_setProperty = d3_style_prototype.setProperty;
    d3_style_prototype.setProperty = function(name, value, priority) {
      d3_style_setProperty.call(this, name, value + "", priority);
    };
  }
  d3 = {version: "2.4.4"}; // semver
  var d3_array = d3_arraySlice; // conversion for NodeLists
  
  function d3_arrayCopy(pseudoarray) {
    var i = -1, n = pseudoarray.length, array = [];
    while (++i < n) array.push(pseudoarray[i]);
    return array;
  }
  
  function d3_arraySlice(pseudoarray) {
    return Array.prototype.slice.call(pseudoarray);
  }
  
  try {
    d3_array(document.documentElement.childNodes)[0].nodeType;
  } catch(e) {
    d3_array = d3_arrayCopy;
  }
  
  var d3_arraySubclass = [].__proto__?
  
  // Until ECMAScript supports array subclassing, prototype injection works well.
  function(array, prototype) {
    array.__proto__ = prototype;
  }:
  
  // And if your browser doesn't support __proto__, we'll use direct extension.
  function(array, prototype) {
    for (var property in prototype) array[property] = prototype[property];
  };
  function d3_this() {
    return this;
  }
  d3.functor = function(v) {
    return typeof v === "function" ? v : function() { return v; };
  };
  // A getter-setter method that preserves the appropriate `this` context.
  d3.rebind = function(object, method) {
    return function() {
      var x = method.apply(object, arguments);
      return arguments.length ? object : x;
    };
  };
  d3.ascending = function(a, b) {
    return a < b ? -1 : a > b ? 1 : a >= b ? 0 : NaN;
  };
  d3.descending = function(a, b) {
    return b < a ? -1 : b > a ? 1 : b >= a ? 0 : NaN;
  };
  d3.mean = function(array, f) {
    var n = array.length,
        a,
        m = 0,
        i = -1,
        j = 0;
    if (arguments.length === 1) {
      while (++i < n) if (d3_number(a = array[i])) m += (a - m) / ++j;
    } else {
      while (++i < n) if (d3_number(a = f.call(array, array[i], i))) m += (a - m) / ++j;
    }
    return j ? m : undefined;
  };
  d3.median = function(array, f) {
    if (arguments.length > 1) array = array.map(f);
    array = array.filter(d3_number);
    return array.length ? d3.quantile(array.sort(d3.ascending), .5) : undefined;
  };
  d3.min = function(array, f) {
    var i = -1,
        n = array.length,
        a,
        b;
    if (arguments.length === 1) {
      while (++i < n && ((a = array[i]) == null || a != a)) a = undefined;
      while (++i < n) if ((b = array[i]) != null && a > b) a = b;
    } else {
      while (++i < n && ((a = f.call(array, array[i], i)) == null || a != a)) a = undefined;
      while (++i < n) if ((b = f.call(array, array[i], i)) != null && a > b) a = b;
    }
    return a;
  };
  d3.max = function(array, f) {
    var i = -1,
        n = array.length,
        a,
        b;
    if (arguments.length === 1) {
      while (++i < n && ((a = array[i]) == null || a != a)) a = undefined;
      while (++i < n) if ((b = array[i]) != null && b > a) a = b;
    } else {
      while (++i < n && ((a = f.call(array, array[i], i)) == null || a != a)) a = undefined;
      while (++i < n) if ((b = f.call(array, array[i], i)) != null && b > a) a = b;
    }
    return a;
  };
  function d3_number(x) {
    return x != null && !isNaN(x);
  }
  d3.sum = function(array, f) {
    var s = 0,
        n = array.length,
        a,
        i = -1;
  
    if (arguments.length === 1) {
      while (++i < n) if (!isNaN(a = +array[i])) s += a;
    } else {
      while (++i < n) if (!isNaN(a = +f.call(array, array[i], i))) s += a;
    }
  
    return s;
  };
  // R-7 per <http://en.wikipedia.org/wiki/Quantile>
  d3.quantile = function(values, p) {
    var H = (values.length - 1) * p + 1,
        h = Math.floor(H),
        v = values[h - 1],
        e = H - h;
    return e ? v + e * (values[h] - v) : v;
  };
  d3.zip = function() {
    if (!(n = arguments.length)) return [];
    for (var i = -1, m = d3.min(arguments, d3_zipLength), zips = new Array(m); ++i < m;) {
      for (var j = -1, n, zip = zips[i] = new Array(n); ++j < n;) {
        zip[j] = arguments[j][i];
      }
    }
    return zips;
  };
  
  function d3_zipLength(d) {
    return d.length;
  }
  // Locate the insertion point for x in a to maintain sorted order. The
  // arguments lo and hi may be used to specify a subset of the array which should
  // be considered; by default the entire array is used. If x is already present
  // in a, the insertion point will be before (to the left of) any existing
  // entries. The return value is suitable for use as the first argument to
  // `array.splice` assuming that a is already sorted.
  //
  // The returned insertion point i partitions the array a into two halves so that
  // all v < x for v in a[lo:i] for the left side and all v >= x for v in a[i:hi]
  // for the right side.
  d3.bisectLeft = function(a, x, lo, hi) {
    if (arguments.length < 3) lo = 0;
    if (arguments.length < 4) hi = a.length;
    while (lo < hi) {
      var mid = (lo + hi) >> 1;
      if (a[mid] < x) lo = mid + 1;
      else hi = mid;
    }
    return lo;
  };
  
  // Similar to bisectLeft, but returns an insertion point which comes after (to
  // the right of) any existing entries of x in a.
  //
  // The returned insertion point i partitions the array into two halves so that
  // all v <= x for v in a[lo:i] for the left side and all v > x for v in a[i:hi]
  // for the right side.
  d3.bisect =
  d3.bisectRight = function(a, x, lo, hi) {
    if (arguments.length < 3) lo = 0;
    if (arguments.length < 4) hi = a.length;
    while (lo < hi) {
      var mid = (lo + hi) >> 1;
      if (x < a[mid]) hi = mid;
      else lo = mid + 1;
    }
    return lo;
  };
  d3.first = function(array, f) {
    var i = 0,
        n = array.length,
        a = array[0],
        b;
    if (arguments.length === 1) f = d3.ascending;
    while (++i < n) {
      if (f.call(array, a, b = array[i]) > 0) {
        a = b;
      }
    }
    return a;
  };
  d3.last = function(array, f) {
    var i = 0,
        n = array.length,
        a = array[0],
        b;
    if (arguments.length === 1) f = d3.ascending;
    while (++i < n) {
      if (f.call(array, a, b = array[i]) <= 0) {
        a = b;
      }
    }
    return a;
  };
  d3.nest = function() {
    var nest = {},
        keys = [],
        sortKeys = [],
        sortValues,
        rollup;
  
    function map(array, depth) {
      if (depth >= keys.length) return rollup
          ? rollup.call(nest, array) : (sortValues
          ? array.sort(sortValues)
          : array);
  
      var i = -1,
          n = array.length,
          key = keys[depth++],
          keyValue,
          object,
          o = {};
  
      while (++i < n) {
        if ((keyValue = key(object = array[i])) in o) {
          o[keyValue].push(object);
        } else {
          o[keyValue] = [object];
        }
      }
  
      for (keyValue in o) {
        o[keyValue] = map(o[keyValue], depth);
      }
  
      return o;
    }
  
    function entries(map, depth) {
      if (depth >= keys.length) return map;
  
      var a = [],
          sortKey = sortKeys[depth++],
          key;
  
      for (key in map) {
        a.push({key: key, values: entries(map[key], depth)});
      }
  
      if (sortKey) a.sort(function(a, b) {
        return sortKey(a.key, b.key);
      });
  
      return a;
    }
  
    nest.map = function(array) {
      return map(array, 0);
    };
  
    nest.entries = function(array) {
      return entries(map(array, 0), 0);
    };
  
    nest.key = function(d) {
      keys.push(d);
      return nest;
    };
  
    // Specifies the order for the most-recently specified key.
    // Note: only applies to entries. Map keys are unordered!
    nest.sortKeys = function(order) {
      sortKeys[keys.length - 1] = order;
      return nest;
    };
  
    // Specifies the order for leaf values.
    // Applies to both maps and entries array.
    nest.sortValues = function(order) {
      sortValues = order;
      return nest;
    };
  
    nest.rollup = function(f) {
      rollup = f;
      return nest;
    };
  
    return nest;
  };
  d3.keys = function(map) {
    var keys = [];
    for (var key in map) keys.push(key);
    return keys;
  };
  d3.values = function(map) {
    var values = [];
    for (var key in map) values.push(map[key]);
    return values;
  };
  d3.entries = function(map) {
    var entries = [];
    for (var key in map) entries.push({key: key, value: map[key]});
    return entries;
  };
  d3.permute = function(array, indexes) {
    var permutes = [],
        i = -1,
        n = indexes.length;
    while (++i < n) permutes[i] = array[indexes[i]];
    return permutes;
  };
  d3.merge = function(arrays) {
    return Array.prototype.concat.apply([], arrays);
  };
  d3.split = function(array, f) {
    var arrays = [],
        values = [],
        value,
        i = -1,
        n = array.length;
    if (arguments.length < 2) f = d3_splitter;
    while (++i < n) {
      if (f.call(values, value = array[i], i)) {
        values = [];
      } else {
        if (!values.length) arrays.push(values);
        values.push(value);
      }
    }
    return arrays;
  };
  
  function d3_splitter(d) {
    return d == null;
  }
  function d3_collapse(s) {
    return s.replace(/(^\s+)|(\s+$)/g, "").replace(/\s+/g, " ");
  }
  /**
   * @param {number} start
   * @param {number=} stop
   * @param {number=} step
   */
  d3.range = function(start, stop, step) {
    if (arguments.length < 3) {
      step = 1;
      if (arguments.length < 2) {
        stop = start;
        start = 0;
      }
    }
    if ((stop - start) / step == Infinity) throw new Error("infinite range");
    var range = [],
         i = -1,
         j;
    if (step < 0) while ((j = start + step * ++i) > stop) range.push(j);
    else while ((j = start + step * ++i) < stop) range.push(j);
    return range;
  };
  d3.requote = function(s) {
    return s.replace(d3_requote_re, "\\$&");
  };
  
  var d3_requote_re = /[\\\^\$\*\+\?\|\[\]\(\)\.\{\}]/g;
  d3.round = function(x, n) {
    return n
        ? Math.round(x * Math.pow(10, n)) * Math.pow(10, -n)
        : Math.round(x);
  };
  d3.xhr = function(url, mime, callback) {
    var req = new XMLHttpRequest;
    if (arguments.length < 3) callback = mime;
    else if (mime && req.overrideMimeType) req.overrideMimeType(mime);
    req.open("GET", url, true);
    req.onreadystatechange = function() {
      if (req.readyState === 4) callback(req.status < 300 ? req : null);
    };
    req.send(null);
  };
  d3.text = function(url, mime, callback) {
    function ready(req) {
      callback(req && req.responseText);
    }
    if (arguments.length < 3) {
      callback = mime;
      mime = null;
    }
    d3.xhr(url, mime, ready);
  };
  d3.json = function(url, callback) {
    d3.text(url, "application/json", function(text) {
      callback(text ? JSON.parse(text) : null);
    });
  };
  d3.html = function(url, callback) {
    d3.text(url, "text/html", function(text) {
      if (text != null) { // Treat empty string as valid HTML.
        var range = document.createRange();
        range.selectNode(document.body);
        text = range.createContextualFragment(text);
      }
      callback(text);
    });
  };
  d3.xml = function(url, mime, callback) {
    function ready(req) {
      callback(req && req.responseXML);
    }
    if (arguments.length < 3) {
      callback = mime;
      mime = null;
    }
    d3.xhr(url, mime, ready);
  };
  d3.ns = {
  
    prefix: {
      svg: "http://www.w3.org/2000/svg",
      xhtml: "http://www.w3.org/1999/xhtml",
      xlink: "http://www.w3.org/1999/xlink",
      xml: "http://www.w3.org/XML/1998/namespace",
      xmlns: "http://www.w3.org/2000/xmlns/"
    },
  
    qualify: function(name) {
      var i = name.indexOf(":");
      return i < 0 ? name : {
        space: d3.ns.prefix[name.substring(0, i)],
        local: name.substring(i + 1)
      };
    }
  
  };
  /** @param {...string} types */
  d3.dispatch = function(types) {
    var dispatch = {},
        type;
    for (var i = 0, n = arguments.length; i < n; i++) {
      type = arguments[i];
      dispatch[type] = d3_dispatch(type);
    }
    return dispatch;
  };
  
  function d3_dispatch(type) {
    var dispatch = {},
        listeners = [];
  
    dispatch.add = function(listener) {
      for (var i = 0; i < listeners.length; i++) {
        if (listeners[i].listener == listener) return dispatch; // already registered
      }
      listeners.push({listener: listener, on: true});
      return dispatch;
    };
  
    dispatch.remove = function(listener) {
      for (var i = 0; i < listeners.length; i++) {
        var l = listeners[i];
        if (l.listener == listener) {
          l.on = false;
          listeners = listeners.slice(0, i).concat(listeners.slice(i + 1));
          break;
        }
      }
      return dispatch;
    };
  
    dispatch.dispatch = function() {
      var ls = listeners; // defensive reference
      for (var i = 0, n = ls.length; i < n; i++) {
        var l = ls[i];
        if (l.on) l.listener.apply(this, arguments);
      }
    };
  
    return dispatch;
  };
  // TODO align
  d3.format = function(specifier) {
    var match = d3_format_re.exec(specifier),
        fill = match[1] || " ",
        sign = match[3] || "",
        zfill = match[5],
        width = +match[6],
        comma = match[7],
        precision = match[8],
        type = match[9],
        scale = 1,
        suffix = "",
        integer = false;
  
    if (precision) precision = +precision.substring(1);
  
    if (zfill) {
      fill = "0"; // TODO align = "=";
      if (comma) width -= Math.floor((width - 1) / 4);
    }
  
    switch (type) {
      case "n": comma = true; type = "g"; break;
      case "%": scale = 100; suffix = "%"; type = "f"; break;
      case "p": scale = 100; suffix = "%"; type = "r"; break;
      case "d": integer = true; precision = 0; break;
      case "s": scale = -1; type = "r"; break;
    }
  
    // If no precision is specified for r, fallback to general notation.
    if (type == "r" && !precision) type = "g";
  
    type = d3_format_types[type] || d3_format_typeDefault;
  
    return function(value) {
  
      // Return the empty string for floats formatted as ints.
      if (integer && (value % 1)) return "";
  
      // Convert negative to positive, and record the sign prefix.
      var negative = (value < 0) && (value = -value) ? "\u2212" : sign;
  
      // Apply the scale, computing it from the value's exponent for si format.
      if (scale < 0) {
        var prefix = d3.formatPrefix(value, precision);
        value *= prefix.scale;
        suffix = prefix.symbol;
      } else {
        value *= scale;
      }
  
      // Convert to the desired precision.
      value = type(value, precision);
  
      // If the fill character is 0, the sign and group is applied after the fill.
      if (zfill) {
        var length = value.length + negative.length;
        if (length < width) value = new Array(width - length + 1).join(fill) + value;
        if (comma) value = d3_format_group(value);
        value = negative + value;
      }
  
      // Otherwise (e.g., space-filling), the sign and group is applied before.
      else {
        if (comma) value = d3_format_group(value);
        value = negative + value;
        var length = value.length;
        if (length < width) value = new Array(width - length + 1).join(fill) + value;
      }
  
      return value + suffix;
    };
  };
  
  // [[fill]align][sign][#][0][width][,][.precision][type]
  var d3_format_re = /(?:([^{])?([<>=^]))?([+\- ])?(#)?(0)?([0-9]+)?(,)?(\.[0-9]+)?([a-zA-Z%])?/;
  
  var d3_format_types = {
    g: function(x, p) { return x.toPrecision(p); },
    e: function(x, p) { return x.toExponential(p); },
    f: function(x, p) { return x.toFixed(p); },
    r: function(x, p) { return d3.round(x, p = d3_format_precision(x, p)).toFixed(Math.max(0, Math.min(20, p))); }
  };
  
  function d3_format_precision(x, p) {
    return p - (x ? 1 + Math.floor(Math.log(x + Math.pow(10, 1 + Math.floor(Math.log(x) / Math.LN10) - p)) / Math.LN10) : 1);
  }
  
  function d3_format_typeDefault(x) {
    return x + "";
  }
  
  // Apply comma grouping for thousands.
  function d3_format_group(value) {
    var i = value.lastIndexOf("."),
        f = i >= 0 ? value.substring(i) : (i = value.length, ""),
        t = [];
    while (i > 0) t.push(value.substring(i -= 3, i + 3));
    return t.reverse().join(",") + f;
  }
  var d3_formatPrefixes = ["y","z","a","f","p","n","μ","m","","k","M","G","T","P","E","Z","Y"].map(d3_formatPrefix);
  
  d3.formatPrefix = function(value, precision) {
    var i = 0;
    if (value) {
      if (value < 0) value *= -1;
      if (precision) value = d3.round(value, d3_format_precision(value, precision));
      i = 1 + Math.floor(1e-12 + Math.log(value) / Math.LN10);
      i = Math.max(-24, Math.min(24, Math.floor((i <= 0 ? i + 1 : i - 1) / 3) * 3));
    }
    return d3_formatPrefixes[8 + i / 3];
  };
  
  function d3_formatPrefix(d, i) {
    return {
      scale: Math.pow(10, (8 - i) * 3),
      symbol: d
    };
  }
  
  /*
   * TERMS OF USE - EASING EQUATIONS
   *
   * Open source under the BSD License.
   *
   * Copyright 2001 Robert Penner
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   * - Redistributions of source code must retain the above copyright notice, this
   *   list of conditions and the following disclaimer.
   *
   * - Redistributions in binary form must reproduce the above copyright notice,
   *   this list of conditions and the following disclaimer in the documentation
   *   and/or other materials provided with the distribution.
   *
   * - Neither the name of the author nor the names of contributors may be used to
   *   endorse or promote products derived from this software without specific
   *   prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   */
  
  var d3_ease_quad = d3_ease_poly(2),
      d3_ease_cubic = d3_ease_poly(3);
  
  var d3_ease = {
    linear: function() { return d3_ease_linear; },
    poly: d3_ease_poly,
    quad: function() { return d3_ease_quad; },
    cubic: function() { return d3_ease_cubic; },
    sin: function() { return d3_ease_sin; },
    exp: function() { return d3_ease_exp; },
    circle: function() { return d3_ease_circle; },
    elastic: d3_ease_elastic,
    back: d3_ease_back,
    bounce: function() { return d3_ease_bounce; }
  };
  
  var d3_ease_mode = {
    "in": function(f) { return f; },
    "out": d3_ease_reverse,
    "in-out": d3_ease_reflect,
    "out-in": function(f) { return d3_ease_reflect(d3_ease_reverse(f)); }
  };
  
  d3.ease = function(name) {
    var i = name.indexOf("-"),
        t = i >= 0 ? name.substring(0, i) : name,
        m = i >= 0 ? name.substring(i + 1) : "in";
    return d3_ease_clamp(d3_ease_mode[m](d3_ease[t].apply(null, Array.prototype.slice.call(arguments, 1))));
  };
  
  function d3_ease_clamp(f) {
    return function(t) {
      return t <= 0 ? 0 : t >= 1 ? 1 : f(t);
    };
  }
  
  function d3_ease_reverse(f) {
    return function(t) {
      return 1 - f(1 - t);
    };
  }
  
  function d3_ease_reflect(f) {
    return function(t) {
      return .5 * (t < .5 ? f(2 * t) : (2 - f(2 - 2 * t)));
    };
  }
  
  function d3_ease_linear(t) {
    return t;
  }
  
  function d3_ease_poly(e) {
    return function(t) {
      return Math.pow(t, e);
    }
  }
  
  function d3_ease_sin(t) {
    return 1 - Math.cos(t * Math.PI / 2);
  }
  
  function d3_ease_exp(t) {
    return Math.pow(2, 10 * (t - 1));
  }
  
  function d3_ease_circle(t) {
    return 1 - Math.sqrt(1 - t * t);
  }
  
  function d3_ease_elastic(a, p) {
    var s;
    if (arguments.length < 2) p = 0.45;
    if (arguments.length < 1) { a = 1; s = p / 4; }
    else s = p / (2 * Math.PI) * Math.asin(1 / a);
    return function(t) {
      return 1 + a * Math.pow(2, 10 * -t) * Math.sin((t - s) * 2 * Math.PI / p);
    };
  }
  
  function d3_ease_back(s) {
    if (!s) s = 1.70158;
    return function(t) {
      return t * t * ((s + 1) * t - s);
    };
  }
  
  function d3_ease_bounce(t) {
    return t < 1 / 2.75 ? 7.5625 * t * t
        : t < 2 / 2.75 ? 7.5625 * (t -= 1.5 / 2.75) * t + .75
        : t < 2.5 / 2.75 ? 7.5625 * (t -= 2.25 / 2.75) * t + .9375
        : 7.5625 * (t -= 2.625 / 2.75) * t + .984375;
  }
  d3.event = null;
  d3.interpolate = function(a, b) {
    var i = d3.interpolators.length, f;
    while (--i >= 0 && !(f = d3.interpolators[i](a, b)));
    return f;
  };
  
  d3.interpolateNumber = function(a, b) {
    b -= a;
    return function(t) { return a + b * t; };
  };
  
  d3.interpolateRound = function(a, b) {
    b -= a;
    return function(t) { return Math.round(a + b * t); };
  };
  
  d3.interpolateString = function(a, b) {
    var m, // current match
        i, // current index
        j, // current index (for coallescing)
        s0 = 0, // start index of current string prefix
        s1 = 0, // end index of current string prefix
        s = [], // string constants and placeholders
        q = [], // number interpolators
        n, // q.length
        o;
  
    // Reset our regular expression!
    d3_interpolate_number.lastIndex = 0;
  
    // Find all numbers in b.
    for (i = 0; m = d3_interpolate_number.exec(b); ++i) {
      if (m.index) s.push(b.substring(s0, s1 = m.index));
      q.push({i: s.length, x: m[0]});
      s.push(null);
      s0 = d3_interpolate_number.lastIndex;
    }
    if (s0 < b.length) s.push(b.substring(s0));
  
    // Find all numbers in a.
    for (i = 0, n = q.length; (m = d3_interpolate_number.exec(a)) && i < n; ++i) {
      o = q[i];
      if (o.x == m[0]) { // The numbers match, so coallesce.
        if (o.i) {
          if (s[o.i + 1] == null) { // This match is followed by another number.
            s[o.i - 1] += o.x;
            s.splice(o.i, 1);
            for (j = i + 1; j < n; ++j) q[j].i--;
          } else { // This match is followed by a string, so coallesce twice.
            s[o.i - 1] += o.x + s[o.i + 1];
            s.splice(o.i, 2);
            for (j = i + 1; j < n; ++j) q[j].i -= 2;
          }
        } else {
            if (s[o.i + 1] == null) { // This match is followed by another number.
            s[o.i] = o.x;
          } else { // This match is followed by a string, so coallesce twice.
            s[o.i] = o.x + s[o.i + 1];
            s.splice(o.i + 1, 1);
            for (j = i + 1; j < n; ++j) q[j].i--;
          }
        }
        q.splice(i, 1);
        n--;
        i--;
      } else {
        o.x = d3.interpolateNumber(parseFloat(m[0]), parseFloat(o.x));
      }
    }
  
    // Remove any numbers in b not found in a.
    while (i < n) {
      o = q.pop();
      if (s[o.i + 1] == null) { // This match is followed by another number.
        s[o.i] = o.x;
      } else { // This match is followed by a string, so coallesce twice.
        s[o.i] = o.x + s[o.i + 1];
        s.splice(o.i + 1, 1);
      }
      n--;
    }
  
    // Special optimization for only a single match.
    if (s.length === 1) {
      return s[0] == null ? q[0].x : function() { return b; };
    }
  
    // Otherwise, interpolate each of the numbers and rejoin the string.
    return function(t) {
      for (i = 0; i < n; ++i) s[(o = q[i]).i] = o.x(t);
      return s.join("");
    };
  };
  
  d3.interpolateRgb = function(a, b) {
    a = d3.rgb(a);
    b = d3.rgb(b);
    var ar = a.r,
        ag = a.g,
        ab = a.b,
        br = b.r - ar,
        bg = b.g - ag,
        bb = b.b - ab;
    return function(t) {
      return "#"
          + d3_rgb_hex(Math.round(ar + br * t))
          + d3_rgb_hex(Math.round(ag + bg * t))
          + d3_rgb_hex(Math.round(ab + bb * t));
    };
  };
  
  // interpolates HSL space, but outputs RGB string (for compatibility)
  d3.interpolateHsl = function(a, b) {
    a = d3.hsl(a);
    b = d3.hsl(b);
    var h0 = a.h,
        s0 = a.s,
        l0 = a.l,
        h1 = b.h - h0,
        s1 = b.s - s0,
        l1 = b.l - l0;
    return function(t) {
      return d3_hsl_rgb(h0 + h1 * t, s0 + s1 * t, l0 + l1 * t).toString();
    };
  };
  
  d3.interpolateArray = function(a, b) {
    var x = [],
        c = [],
        na = a.length,
        nb = b.length,
        n0 = Math.min(a.length, b.length),
        i;
    for (i = 0; i < n0; ++i) x.push(d3.interpolate(a[i], b[i]));
    for (; i < na; ++i) c[i] = a[i];
    for (; i < nb; ++i) c[i] = b[i];
    return function(t) {
      for (i = 0; i < n0; ++i) c[i] = x[i](t);
      return c;
    };
  };
  
  d3.interpolateObject = function(a, b) {
    var i = {},
        c = {},
        k;
    for (k in a) {
      if (k in b) {
        i[k] = d3_interpolateByName(k)(a[k], b[k]);
      } else {
        c[k] = a[k];
      }
    }
    for (k in b) {
      if (!(k in a)) {
        c[k] = b[k];
      }
    }
    return function(t) {
      for (k in i) c[k] = i[k](t);
      return c;
    };
  }
  
  var d3_interpolate_number = /[-+]?(?:\d+\.\d+|\d+\.|\.\d+|\d+)(?:[eE][-]?\d+)?/g,
      d3_interpolate_rgb = {background: 1, fill: 1, stroke: 1};
  
  function d3_interpolateByName(n) {
    return n in d3_interpolate_rgb || /\bcolor\b/.test(n)
        ? d3.interpolateRgb
        : d3.interpolate;
  }
  
  d3.interpolators = [
    d3.interpolateObject,
    function(a, b) { return (b instanceof Array) && d3.interpolateArray(a, b); },
    function(a, b) { return (typeof b === "string") && d3.interpolateString(String(a), b); },
    function(a, b) { return (typeof b === "string" ? b in d3_rgb_names || /^(#|rgb\(|hsl\()/.test(b) : b instanceof d3_Rgb || b instanceof d3_Hsl) && d3.interpolateRgb(String(a), b); },
    function(a, b) { return (typeof b === "number") && d3.interpolateNumber(+a, b); }
  ];
  function d3_uninterpolateNumber(a, b) {
    b = b - (a = +a) ? 1 / (b - a) : 0;
    return function(x) { return (x - a) * b; };
  }
  
  function d3_uninterpolateClamp(a, b) {
    b = b - (a = +a) ? 1 / (b - a) : 0;
    return function(x) { return Math.max(0, Math.min(1, (x - a) * b)); };
  }
  d3.rgb = function(r, g, b) {
    return arguments.length === 1
        ? (r instanceof d3_Rgb ? d3_rgb(r.r, r.g, r.b)
        : d3_rgb_parse("" + r, d3_rgb, d3_hsl_rgb))
        : d3_rgb(~~r, ~~g, ~~b);
  };
  
  function d3_rgb(r, g, b) {
    return new d3_Rgb(r, g, b);
  }
  
  function d3_Rgb(r, g, b) {
    this.r = r;
    this.g = g;
    this.b = b;
  }
  
  d3_Rgb.prototype.brighter = function(k) {
    k = Math.pow(0.7, arguments.length ? k : 1);
    var r = this.r,
        g = this.g,
        b = this.b,
        i = 30;
    if (!r && !g && !b) return d3_rgb(i, i, i);
    if (r && r < i) r = i;
    if (g && g < i) g = i;
    if (b && b < i) b = i;
    return d3_rgb(
        Math.min(255, Math.floor(r / k)),
        Math.min(255, Math.floor(g / k)),
        Math.min(255, Math.floor(b / k)));
  };
  
  d3_Rgb.prototype.darker = function(k) {
    k = Math.pow(0.7, arguments.length ? k : 1);
    return d3_rgb(
        Math.floor(k * this.r),
        Math.floor(k * this.g),
        Math.floor(k * this.b));
  };
  
  d3_Rgb.prototype.hsl = function() {
    return d3_rgb_hsl(this.r, this.g, this.b);
  };
  
  d3_Rgb.prototype.toString = function() {
    return "#" + d3_rgb_hex(this.r) + d3_rgb_hex(this.g) + d3_rgb_hex(this.b);
  };
  
  function d3_rgb_hex(v) {
    return v < 0x10
        ? "0" + Math.max(0, v).toString(16)
        : Math.min(255, v).toString(16);
  }
  
  function d3_rgb_parse(format, rgb, hsl) {
    var r = 0, // red channel; int in [0, 255]
        g = 0, // green channel; int in [0, 255]
        b = 0, // blue channel; int in [0, 255]
        m1, // CSS color specification match
        m2, // CSS color specification type (e.g., rgb)
        name;
  
    /* Handle hsl, rgb. */
    m1 = /([a-z]+)\((.*)\)/i.exec(format);
    if (m1) {
      m2 = m1[2].split(",");
      switch (m1[1]) {
        case "hsl": {
          return hsl(
            parseFloat(m2[0]), // degrees
            parseFloat(m2[1]) / 100, // percentage
            parseFloat(m2[2]) / 100 // percentage
          );
        }
        case "rgb": {
          return rgb(
            d3_rgb_parseNumber(m2[0]),
            d3_rgb_parseNumber(m2[1]),
            d3_rgb_parseNumber(m2[2])
          );
        }
      }
    }
  
    /* Named colors. */
    if (name = d3_rgb_names[format]) return rgb(name.r, name.g, name.b);
  
    /* Hexadecimal colors: #rgb and #rrggbb. */
    if (format != null && format.charAt(0) === "#") {
      if (format.length === 4) {
        r = format.charAt(1); r += r;
        g = format.charAt(2); g += g;
        b = format.charAt(3); b += b;
      } else if (format.length === 7) {
        r = format.substring(1, 3);
        g = format.substring(3, 5);
        b = format.substring(5, 7);
      }
      r = parseInt(r, 16);
      g = parseInt(g, 16);
      b = parseInt(b, 16);
    }
  
    return rgb(r, g, b);
  }
  
  function d3_rgb_hsl(r, g, b) {
    var min = Math.min(r /= 255, g /= 255, b /= 255),
        max = Math.max(r, g, b),
        d = max - min,
        h,
        s,
        l = (max + min) / 2;
    if (d) {
      s = l < .5 ? d / (max + min) : d / (2 - max - min);
      if (r == max) h = (g - b) / d + (g < b ? 6 : 0);
      else if (g == max) h = (b - r) / d + 2;
      else h = (r - g) / d + 4;
      h *= 60;
    } else {
      s = h = 0;
    }
    return d3_hsl(h, s, l);
  }
  
  function d3_rgb_parseNumber(c) { // either integer or percentage
    var f = parseFloat(c);
    return c.charAt(c.length - 1) === "%" ? Math.round(f * 2.55) : f;
  }
  
  var d3_rgb_names = {
    aliceblue: "#f0f8ff",
    antiquewhite: "#faebd7",
    aqua: "#00ffff",
    aquamarine: "#7fffd4",
    azure: "#f0ffff",
    beige: "#f5f5dc",
    bisque: "#ffe4c4",
    black: "#000000",
    blanchedalmond: "#ffebcd",
    blue: "#0000ff",
    blueviolet: "#8a2be2",
    brown: "#a52a2a",
    burlywood: "#deb887",
    cadetblue: "#5f9ea0",
    chartreuse: "#7fff00",
    chocolate: "#d2691e",
    coral: "#ff7f50",
    cornflowerblue: "#6495ed",
    cornsilk: "#fff8dc",
    crimson: "#dc143c",
    cyan: "#00ffff",
    darkblue: "#00008b",
    darkcyan: "#008b8b",
    darkgoldenrod: "#b8860b",
    darkgray: "#a9a9a9",
    darkgreen: "#006400",
    darkgrey: "#a9a9a9",
    darkkhaki: "#bdb76b",
    darkmagenta: "#8b008b",
    darkolivegreen: "#556b2f",
    darkorange: "#ff8c00",
    darkorchid: "#9932cc",
    darkred: "#8b0000",
    darksalmon: "#e9967a",
    darkseagreen: "#8fbc8f",
    darkslateblue: "#483d8b",
    darkslategray: "#2f4f4f",
    darkslategrey: "#2f4f4f",
    darkturquoise: "#00ced1",
    darkviolet: "#9400d3",
    deeppink: "#ff1493",
    deepskyblue: "#00bfff",
    dimgray: "#696969",
    dimgrey: "#696969",
    dodgerblue: "#1e90ff",
    firebrick: "#b22222",
    floralwhite: "#fffaf0",
    forestgreen: "#228b22",
    fuchsia: "#ff00ff",
    gainsboro: "#dcdcdc",
    ghostwhite: "#f8f8ff",
    gold: "#ffd700",
    goldenrod: "#daa520",
    gray: "#808080",
    green: "#008000",
    greenyellow: "#adff2f",
    grey: "#808080",
    honeydew: "#f0fff0",
    hotpink: "#ff69b4",
    indianred: "#cd5c5c",
    indigo: "#4b0082",
    ivory: "#fffff0",
    khaki: "#f0e68c",
    lavender: "#e6e6fa",
    lavenderblush: "#fff0f5",
    lawngreen: "#7cfc00",
    lemonchiffon: "#fffacd",
    lightblue: "#add8e6",
    lightcoral: "#f08080",
    lightcyan: "#e0ffff",
    lightgoldenrodyellow: "#fafad2",
    lightgray: "#d3d3d3",
    lightgreen: "#90ee90",
    lightgrey: "#d3d3d3",
    lightpink: "#ffb6c1",
    lightsalmon: "#ffa07a",
    lightseagreen: "#20b2aa",
    lightskyblue: "#87cefa",
    lightslategray: "#778899",
    lightslategrey: "#778899",
    lightsteelblue: "#b0c4de",
    lightyellow: "#ffffe0",
    lime: "#00ff00",
    limegreen: "#32cd32",
    linen: "#faf0e6",
    magenta: "#ff00ff",
    maroon: "#800000",
    mediumaquamarine: "#66cdaa",
    mediumblue: "#0000cd",
    mediumorchid: "#ba55d3",
    mediumpurple: "#9370db",
    mediumseagreen: "#3cb371",
    mediumslateblue: "#7b68ee",
    mediumspringgreen: "#00fa9a",
    mediumturquoise: "#48d1cc",
    mediumvioletred: "#c71585",
    midnightblue: "#191970",
    mintcream: "#f5fffa",
    mistyrose: "#ffe4e1",
    moccasin: "#ffe4b5",
    navajowhite: "#ffdead",
    navy: "#000080",
    oldlace: "#fdf5e6",
    olive: "#808000",
    olivedrab: "#6b8e23",
    orange: "#ffa500",
    orangered: "#ff4500",
    orchid: "#da70d6",
    palegoldenrod: "#eee8aa",
    palegreen: "#98fb98",
    paleturquoise: "#afeeee",
    palevioletred: "#db7093",
    papayawhip: "#ffefd5",
    peachpuff: "#ffdab9",
    peru: "#cd853f",
    pink: "#ffc0cb",
    plum: "#dda0dd",
    powderblue: "#b0e0e6",
    purple: "#800080",
    red: "#ff0000",
    rosybrown: "#bc8f8f",
    royalblue: "#4169e1",
    saddlebrown: "#8b4513",
    salmon: "#fa8072",
    sandybrown: "#f4a460",
    seagreen: "#2e8b57",
    seashell: "#fff5ee",
    sienna: "#a0522d",
    silver: "#c0c0c0",
    skyblue: "#87ceeb",
    slateblue: "#6a5acd",
    slategray: "#708090",
    slategrey: "#708090",
    snow: "#fffafa",
    springgreen: "#00ff7f",
    steelblue: "#4682b4",
    tan: "#d2b48c",
    teal: "#008080",
    thistle: "#d8bfd8",
    tomato: "#ff6347",
    turquoise: "#40e0d0",
    violet: "#ee82ee",
    wheat: "#f5deb3",
    white: "#ffffff",
    whitesmoke: "#f5f5f5",
    yellow: "#ffff00",
    yellowgreen: "#9acd32"
  };
  
  for (var d3_rgb_name in d3_rgb_names) {
    d3_rgb_names[d3_rgb_name] = d3_rgb_parse(
        d3_rgb_names[d3_rgb_name],
        d3_rgb,
        d3_hsl_rgb);
  }
  d3.hsl = function(h, s, l) {
    return arguments.length === 1
        ? (h instanceof d3_Hsl ? d3_hsl(h.h, h.s, h.l)
        : d3_rgb_parse("" + h, d3_rgb_hsl, d3_hsl))
        : d3_hsl(+h, +s, +l);
  };
  
  function d3_hsl(h, s, l) {
    return new d3_Hsl(h, s, l);
  }
  
  function d3_Hsl(h, s, l) {
    this.h = h;
    this.s = s;
    this.l = l;
  }
  
  d3_Hsl.prototype.brighter = function(k) {
    k = Math.pow(0.7, arguments.length ? k : 1);
    return d3_hsl(this.h, this.s, this.l / k);
  };
  
  d3_Hsl.prototype.darker = function(k) {
    k = Math.pow(0.7, arguments.length ? k : 1);
    return d3_hsl(this.h, this.s, k * this.l);
  };
  
  d3_Hsl.prototype.rgb = function() {
    return d3_hsl_rgb(this.h, this.s, this.l);
  };
  
  d3_Hsl.prototype.toString = function() {
    return this.rgb().toString();
  };
  
  function d3_hsl_rgb(h, s, l) {
    var m1,
        m2;
  
    /* Some simple corrections for h, s and l. */
    h = h % 360; if (h < 0) h += 360;
    s = s < 0 ? 0 : s > 1 ? 1 : s;
    l = l < 0 ? 0 : l > 1 ? 1 : l;
  
    /* From FvD 13.37, CSS Color Module Level 3 */
    m2 = l <= .5 ? l * (1 + s) : l + s - l * s;
    m1 = 2 * l - m2;
  
    function v(h) {
      if (h > 360) h -= 360;
      else if (h < 0) h += 360;
      if (h < 60) return m1 + (m2 - m1) * h / 60;
      if (h < 180) return m2;
      if (h < 240) return m1 + (m2 - m1) * (240 - h) / 60;
      return m1;
    }
  
    function vv(h) {
      return Math.round(v(h) * 255);
    }
  
    return d3_rgb(vv(h + 120), vv(h), vv(h - 120));
  }
  function d3_selection(groups) {
    d3_arraySubclass(groups, d3_selectionPrototype);
    return groups;
  }
  
  var d3_select = function(s, n) { return n.querySelector(s); },
      d3_selectAll = function(s, n) { return n.querySelectorAll(s); };
  
  // Prefer Sizzle, if available.
  if (typeof Sizzle === "function") {
    d3_select = function(s, n) { return Sizzle(s, n)[0]; };
    d3_selectAll = function(s, n) { return Sizzle.uniqueSort(Sizzle(s, n)); };
  }
  
  var d3_selectionPrototype = [];
  
  d3.selection = function() {
    return d3_selectionRoot;
  };
  
  d3.selection.prototype = d3_selectionPrototype;
  d3_selectionPrototype.select = function(selector) {
    var subgroups = [],
        subgroup,
        subnode,
        group,
        node;
  
    if (typeof selector !== "function") selector = d3_selection_selector(selector);
  
    for (var j = -1, m = this.length; ++j < m;) {
      subgroups.push(subgroup = []);
      subgroup.parentNode = (group = this[j]).parentNode;
      for (var i = -1, n = group.length; ++i < n;) {
        if (node = group[i]) {
          subgroup.push(subnode = selector.call(node, node.__data__, i));
          if (subnode && "__data__" in node) subnode.__data__ = node.__data__;
        } else {
          subgroup.push(null);
        }
      }
    }
  
    return d3_selection(subgroups);
  };
  
  function d3_selection_selector(selector) {
    return function() {
      return d3_select(selector, this);
    };
  }
  d3_selectionPrototype.selectAll = function(selector) {
    var subgroups = [],
        subgroup,
        node;
  
    if (typeof selector !== "function") selector = d3_selection_selectorAll(selector);
  
    for (var j = -1, m = this.length; ++j < m;) {
      for (var group = this[j], i = -1, n = group.length; ++i < n;) {
        if (node = group[i]) {
          subgroups.push(subgroup = d3_array(selector.call(node, node.__data__, i)));
          subgroup.parentNode = node;
        }
      }
    }
  
    return d3_selection(subgroups);
  };
  
  function d3_selection_selectorAll(selector) {
    return function() {
      return d3_selectAll(selector, this);
    };
  }
  d3_selectionPrototype.attr = function(name, value) {
    name = d3.ns.qualify(name);
  
    // If no value is specified, return the first value.
    if (arguments.length < 2) {
      var node = this.node();
      return name.local
          ? node.getAttributeNS(name.space, name.local)
          : node.getAttribute(name);
    }
  
    function attrNull() {
      this.removeAttribute(name);
    }
  
    function attrNullNS() {
      this.removeAttributeNS(name.space, name.local);
    }
  
    function attrConstant() {
      this.setAttribute(name, value);
    }
  
    function attrConstantNS() {
      this.setAttributeNS(name.space, name.local, value);
    }
  
    function attrFunction() {
      var x = value.apply(this, arguments);
      if (x == null) this.removeAttribute(name);
      else this.setAttribute(name, x);
    }
  
    function attrFunctionNS() {
      var x = value.apply(this, arguments);
      if (x == null) this.removeAttributeNS(name.space, name.local);
      else this.setAttributeNS(name.space, name.local, x);
    }
  
    return this.each(value == null
        ? (name.local ? attrNullNS : attrNull) : (typeof value === "function"
        ? (name.local ? attrFunctionNS : attrFunction)
        : (name.local ? attrConstantNS : attrConstant)));
  };
  d3_selectionPrototype.classed = function(name, value) {
    var names = name.split(d3_selection_classedWhitespace),
        n = names.length,
        i = -1;
    if (arguments.length > 1) {
      while (++i < n) d3_selection_classed.call(this, names[i], value);
      return this;
    } else {
      while (++i < n) if (!d3_selection_classed.call(this, names[i])) return false;
      return true;
    }
  };
  
  var d3_selection_classedWhitespace = /\s+/g;
  
  function d3_selection_classed(name, value) {
    var re = new RegExp("(^|\\s+)" + d3.requote(name) + "(\\s+|$)", "g");
  
    // If no value is specified, return the first value.
    if (arguments.length < 2) {
      var node = this.node();
      if (c = node.classList) return c.contains(name);
      var c = node.className;
      re.lastIndex = 0;
      return re.test(c.baseVal != null ? c.baseVal : c);
    }
  
    function classedAdd() {
      if (c = this.classList) return c.add(name);
      var c = this.className,
          cb = c.baseVal != null,
          cv = cb ? c.baseVal : c;
      re.lastIndex = 0;
      if (!re.test(cv)) {
        cv = d3_collapse(cv + " " + name);
        if (cb) c.baseVal = cv;
        else this.className = cv;
      }
    }
  
    function classedRemove() {
      if (c = this.classList) return c.remove(name);
      var c = this.className,
          cb = c.baseVal != null,
          cv = cb ? c.baseVal : c;
      cv = d3_collapse(cv.replace(re, " "));
      if (cb) c.baseVal = cv;
      else this.className = cv;
    }
  
    function classedFunction() {
      (value.apply(this, arguments)
          ? classedAdd
          : classedRemove).call(this);
    }
  
    return this.each(typeof value === "function"
        ? classedFunction : value
        ? classedAdd
        : classedRemove);
  }
  d3_selectionPrototype.style = function(name, value, priority) {
    if (arguments.length < 3) priority = "";
  
    // If no value is specified, return the first value.
    if (arguments.length < 2) return window
        .getComputedStyle(this.node(), null)
        .getPropertyValue(name);
  
    function styleNull() {
      this.style.removeProperty(name);
    }
  
    function styleConstant() {
      this.style.setProperty(name, value, priority);
    }
  
    function styleFunction() {
      var x = value.apply(this, arguments);
      if (x == null) this.style.removeProperty(name);
      else this.style.setProperty(name, x, priority);
    }
  
    return this.each(value == null
        ? styleNull : (typeof value === "function"
        ? styleFunction : styleConstant));
  };
  d3_selectionPrototype.property = function(name, value) {
  
    // If no value is specified, return the first value.
    if (arguments.length < 2) return this.node()[name];
  
    function propertyNull() {
      delete this[name];
    }
  
    function propertyConstant() {
      this[name] = value;
    }
  
    function propertyFunction() {
      var x = value.apply(this, arguments);
      if (x == null) delete this[name];
      else this[name] = x;
    }
  
    return this.each(value == null
        ? propertyNull : (typeof value === "function"
        ? propertyFunction : propertyConstant));
  };
  d3_selectionPrototype.text = function(value) {
    return arguments.length < 1 ? this.node().textContent
        : (this.each(typeof value === "function"
        ? function() { this.textContent = value.apply(this, arguments); }
        : function() { this.textContent = value; }));
  };
  d3_selectionPrototype.html = function(value) {
    return arguments.length < 1 ? this.node().innerHTML
        : (this.each(typeof value === "function"
        ? function() { this.innerHTML = value.apply(this, arguments); }
        : function() { this.innerHTML = value; }));
  };
  // TODO append(node)?
  // TODO append(function)?
  d3_selectionPrototype.append = function(name) {
    name = d3.ns.qualify(name);
  
    function append() {
      return this.appendChild(document.createElement(name));
    }
  
    function appendNS() {
      return this.appendChild(document.createElementNS(name.space, name.local));
    }
  
    return this.select(name.local ? appendNS : append);
  };
  // TODO insert(node, function)?
  // TODO insert(function, string)?
  // TODO insert(function, function)?
  d3_selectionPrototype.insert = function(name, before) {
    name = d3.ns.qualify(name);
  
    function insert() {
      return this.insertBefore(
          document.createElement(name),
          d3_select(before, this));
    }
  
    function insertNS() {
      return this.insertBefore(
          document.createElementNS(name.space, name.local),
          d3_select(before, this));
    }
  
    return this.select(name.local ? insertNS : insert);
  };
  // TODO remove(selector)?
  // TODO remove(node)?
  // TODO remove(function)?
  d3_selectionPrototype.remove = function() {
    return this.each(function() {
      var parent = this.parentNode;
      if (parent) parent.removeChild(this);
    });
  };
  // TODO data(null) for clearing data?
  d3_selectionPrototype.data = function(data, join) {
    var enter = [],
        update = [],
        exit = [];
  
    function bind(group, groupData) {
      var i,
          n = group.length,
          m = groupData.length,
          n0 = Math.min(n, m),
          n1 = Math.max(n, m),
          updateNodes = [],
          enterNodes = [],
          exitNodes = [],
          node,
          nodeData;
  
      if (join) {
        var nodeByKey = {},
            keys = [],
            key,
            j = groupData.length;
  
        for (i = -1; ++i < n;) {
          key = join.call(node = group[i], node.__data__, i);
          if (key in nodeByKey) {
            exitNodes[j++] = node; // duplicate key
          } else {
            nodeByKey[key] = node;
          }
          keys.push(key);
        }
  
        for (i = -1; ++i < m;) {
          node = nodeByKey[key = join.call(groupData, nodeData = groupData[i], i)];
          if (node) {
            node.__data__ = nodeData;
            updateNodes[i] = node;
            enterNodes[i] = exitNodes[i] = null;
          } else {
            enterNodes[i] = d3_selection_dataNode(nodeData);
            updateNodes[i] = exitNodes[i] = null;
          }
          delete nodeByKey[key];
        }
  
        for (i = -1; ++i < n;) {
          if (keys[i] in nodeByKey) {
            exitNodes[i] = group[i];
          }
        }
      } else {
        for (i = -1; ++i < n0;) {
          node = group[i];
          nodeData = groupData[i];
          if (node) {
            node.__data__ = nodeData;
            updateNodes[i] = node;
            enterNodes[i] = exitNodes[i] = null;
          } else {
            enterNodes[i] = d3_selection_dataNode(nodeData);
            updateNodes[i] = exitNodes[i] = null;
          }
        }
        for (; i < m; ++i) {
          enterNodes[i] = d3_selection_dataNode(groupData[i]);
          updateNodes[i] = exitNodes[i] = null;
        }
        for (; i < n1; ++i) {
          exitNodes[i] = group[i];
          enterNodes[i] = updateNodes[i] = null;
        }
      }
  
      enterNodes.update
          = updateNodes;
  
      enterNodes.parentNode
          = updateNodes.parentNode
          = exitNodes.parentNode
          = group.parentNode;
  
      enter.push(enterNodes);
      update.push(updateNodes);
      exit.push(exitNodes);
    }
  
    var i = -1,
        n = this.length,
        group;
    if (typeof data === "function") {
      while (++i < n) {
        bind(group = this[i], data.call(group, group.parentNode.__data__, i));
      }
    } else {
      while (++i < n) {
        bind(group = this[i], data);
      }
    }
  
    var selection = d3_selection(update);
    selection.enter = function() { return d3_selection_enter(enter); };
    selection.exit = function() { return d3_selection(exit); };
    return selection;
  };
  
  function d3_selection_dataNode(data) {
    return {__data__: data};
  }
  function d3_selection_enter(selection) {
    d3_arraySubclass(selection, d3_selection_enterPrototype);
    return selection;
  }
  
  var d3_selection_enterPrototype = [];
  
  d3_selection_enterPrototype.append = d3_selectionPrototype.append;
  d3_selection_enterPrototype.insert = d3_selectionPrototype.insert;
  d3_selection_enterPrototype.empty = d3_selectionPrototype.empty;
  d3_selection_enterPrototype.select = function(selector) {
    var subgroups = [],
        subgroup,
        subnode,
        upgroup,
        group,
        node;
  
    for (var j = -1, m = this.length; ++j < m;) {
      upgroup = (group = this[j]).update;
      subgroups.push(subgroup = []);
      subgroup.parentNode = group.parentNode;
      for (var i = -1, n = group.length; ++i < n;) {
        if (node = group[i]) {
          subgroup.push(upgroup[i] = subnode = selector.call(group.parentNode, node.__data__, i));
          subnode.__data__ = node.__data__;
        } else {
          subgroup.push(null);
        }
      }
    }
  
    return d3_selection(subgroups);
  };
  // TODO preserve null elements to maintain index?
  d3_selectionPrototype.filter = function(filter) {
    var subgroups = [],
        subgroup,
        group,
        node;
  
    for (var j = 0, m = this.length; j < m; j++) {
      subgroups.push(subgroup = []);
      subgroup.parentNode = (group = this[j]).parentNode;
      for (var i = 0, n = group.length; i < n; i++) {
        if ((node = group[i]) && filter.call(node, node.__data__, i)) {
          subgroup.push(node);
        }
      }
    }
  
    return d3_selection(subgroups);
  };
  d3_selectionPrototype.map = function(map) {
    return this.each(function() {
      this.__data__ = map.apply(this, arguments);
    });
  };
  d3_selectionPrototype.sort = function(comparator) {
    comparator = d3_selection_sortComparator.apply(this, arguments);
    for (var j = 0, m = this.length; j < m; j++) {
      for (var group = this[j].sort(comparator), i = 1, n = group.length, prev = group[0]; i < n; i++) {
        var node = group[i];
        if (node) {
          if (prev) prev.parentNode.insertBefore(node, prev.nextSibling);
          prev = node;
        }
      }
    }
    return this;
  };
  
  function d3_selection_sortComparator(comparator) {
    if (!arguments.length) comparator = d3.ascending;
    return function(a, b) {
      return comparator(a && a.__data__, b && b.__data__);
    };
  }
  // type can be namespaced, e.g., "click.foo"
  // listener can be null for removal
  d3_selectionPrototype.on = function(type, listener, capture) {
    if (arguments.length < 3) capture = false;
  
    // parse the type specifier
    var name = "__on" + type, i = type.indexOf(".");
    if (i > 0) type = type.substring(0, i);
  
    // if called with only one argument, return the current listener
    if (arguments.length < 2) return (i = this.node()[name]) && i._;
  
    // remove the old event listener, and add the new event listener
    return this.each(function(d, i) {
      var node = this;
  
      if (node[name]) node.removeEventListener(type, node[name], capture);
      if (listener) node.addEventListener(type, node[name] = l, capture);
  
      // wrapped event listener that preserves i
      function l(e) {
        var o = d3.event; // Events can be reentrant (e.g., focus).
        d3.event = e;
        try {
          listener.call(node, node.__data__, i);
        } finally {
          d3.event = o;
        }
      }
  
      // stash the unwrapped listener for retrieval
      l._ = listener;
    });
  };
  d3_selectionPrototype.each = function(callback) {
    for (var j = -1, m = this.length; ++j < m;) {
      for (var group = this[j], i = -1, n = group.length; ++i < n;) {
        var node = group[i];
        if (node) callback.call(node, node.__data__, i, j);
      }
    }
    return this;
  };
  //
  // Note: assigning to the arguments array simultaneously changes the value of
  // the corresponding argument!
  //
  // TODO The `this` argument probably shouldn't be the first argument to the
  // callback, anyway, since it's redundant. However, that will require a major
  // version bump due to backwards compatibility, so I'm not changing it right
  // away.
  //
  d3_selectionPrototype.call = function(callback) {
    callback.apply(this, (arguments[0] = this, arguments));
    return this;
  };
  d3_selectionPrototype.empty = function() {
    return !this.node();
  };
  d3_selectionPrototype.node = function(callback) {
    for (var j = 0, m = this.length; j < m; j++) {
      for (var group = this[j], i = 0, n = group.length; i < n; i++) {
        var node = group[i];
        if (node) return node;
      }
    }
    return null;
  };
  d3_selectionPrototype.transition = function() {
    var subgroups = [],
        subgroup,
        node;
  
    for (var j = -1, m = this.length; ++j < m;) {
      subgroups.push(subgroup = []);
      for (var group = this[j], i = -1, n = group.length; ++i < n;) {
        subgroup.push((node = group[i]) ? {node: node, delay: 0, duration: 250} : null);
      }
    }
  
    return d3_transition(subgroups, d3_transitionInheritId || ++d3_transitionId, Date.now());
  };
  var d3_selectionRoot = d3_selection([[document]]);
  
  d3_selectionRoot[0].parentNode = document.documentElement;
  
  // TODO fast singleton implementation!
  // TODO select(function)
  d3.select = function(selector) {
    return typeof selector === "string"
        ? d3_selectionRoot.select(selector)
        : d3_selection([[selector]]); // assume node
  };
  
  // TODO selectAll(function)
  d3.selectAll = function(selector) {
    return typeof selector === "string"
        ? d3_selectionRoot.selectAll(selector)
        : d3_selection([d3_array(selector)]); // assume node[]
  };
  function d3_transition(groups, id, time) {
    d3_arraySubclass(groups, d3_transitionPrototype);
  
    var tweens = {},
        event = d3.dispatch("start", "end"),
        ease = d3_transitionEase;
  
    groups.id = id;
  
    groups.time = time;
  
    groups.tween = function(name, tween) {
      if (arguments.length < 2) return tweens[name];
      if (tween == null) delete tweens[name];
      else tweens[name] = tween;
      return groups;
    };
  
    groups.ease = function(value) {
      if (!arguments.length) return ease;
      ease = typeof value === "function" ? value : d3.ease.apply(d3, arguments);
      return groups;
    };
  
    groups.each = function(type, listener) {
      if (arguments.length < 2) return d3_transition_each.call(groups, type);
      event[type].add(listener);
      return groups;
    };
  
    d3.timer(function(elapsed) {
      groups.each(function(d, i, j) {
        var tweened = [],
            node = this,
            delay = groups[j][i].delay,
            duration = groups[j][i].duration,
            lock = node.__transition__ || (node.__transition__ = {active: 0, count: 0});
  
        ++lock.count;
  
        delay <= elapsed ? start(elapsed) : d3.timer(start, delay, time);
  
        function start(elapsed) {
          if (lock.active > id) return stop();
          lock.active = id;
  
          for (var tween in tweens) {
            if (tween = tweens[tween].call(node, d, i)) {
              tweened.push(tween);
            }
          }
  
          event.start.dispatch.call(node, d, i);
          if (!tick(elapsed)) d3.timer(tick, 0, time);
          return 1;
        }
  
        function tick(elapsed) {
          if (lock.active !== id) return stop();
  
          var t = (elapsed - delay) / duration,
              e = ease(t),
              n = tweened.length;
  
          while (n > 0) {
            tweened[--n].call(node, e);
          }
  
          if (t >= 1) {
            stop();
            d3_transitionInheritId = id;
            event.end.dispatch.call(node, d, i);
            d3_transitionInheritId = 0;
            return 1;
          }
        }
  
        function stop() {
          if (!--lock.count) delete node.__transition__;
          return 1;
        }
      });
      return 1;
    }, 0, time);
  
    return groups;
  }
  
  var d3_transitionRemove = {};
  
  function d3_transitionNull(d, i, a) {
    return a != "" && d3_transitionRemove;
  }
  
  function d3_transitionTween(b) {
  
    function transitionFunction(d, i, a) {
      var v = b.call(this, d, i);
      return v == null
          ? a != "" && d3_transitionRemove
          : a != v && d3.interpolate(a, v);
    }
  
    function transitionString(d, i, a) {
      return a != b && d3.interpolate(a, b);
    }
  
    return typeof b === "function" ? transitionFunction
        : b == null ? d3_transitionNull
        : (b += "", transitionString);
  }
  
  var d3_transitionPrototype = [],
      d3_transitionId = 0,
      d3_transitionInheritId = 0,
      d3_transitionEase = d3.ease("cubic-in-out");
  
  d3_transitionPrototype.call = d3_selectionPrototype.call;
  
  d3.transition = function() {
    return d3_selectionRoot.transition();
  };
  
  d3.transition.prototype = d3_transitionPrototype;
  d3_transitionPrototype.select = function(selector) {
    var subgroups = [],
        subgroup,
        subnode,
        node;
  
    if (typeof selector !== "function") selector = d3_selection_selector(selector);
  
    for (var j = -1, m = this.length; ++j < m;) {
      subgroups.push(subgroup = []);
      for (var group = this[j], i = -1, n = group.length; ++i < n;) {
        if ((node = group[i]) && (subnode = selector.call(node.node, node.node.__data__, i))) {
          if ("__data__" in node.node) subnode.__data__ = node.node.__data__;
          subgroup.push({node: subnode, delay: node.delay, duration: node.duration});
        } else {
          subgroup.push(null);
        }
      }
    }
  
    return d3_transition(subgroups, this.id, this.time).ease(this.ease());
  };
  d3_transitionPrototype.selectAll = function(selector) {
    var subgroups = [],
        subgroup,
        subnodes,
        node;
  
    if (typeof selector !== "function") selector = d3_selection_selectorAll(selector);
  
    for (var j = -1, m = this.length; ++j < m;) {
      for (var group = this[j], i = -1, n = group.length; ++i < n;) {
        if (node = group[i]) {
          subnodes = selector.call(node.node, node.node.__data__, i);
          subgroups.push(subgroup = []);
          for (var k = -1, o = subnodes.length; ++k < o;) {
            subgroup.push({node: subnodes[k], delay: node.delay, duration: node.duration});
          }
        }
      }
    }
  
    return d3_transition(subgroups, this.id, this.time).ease(this.ease());
  };
  d3_transitionPrototype.attr = function(name, value) {
    return this.attrTween(name, d3_transitionTween(value));
  };
  
  d3_transitionPrototype.attrTween = function(nameNS, tween) {
    var name = d3.ns.qualify(nameNS);
  
    function attrTween(d, i) {
      var f = tween.call(this, d, i, this.getAttribute(name));
      return f === d3_transitionRemove
          ? (this.removeAttribute(name), null)
          : f && function(t) { this.setAttribute(name, f(t)); };
    }
  
    function attrTweenNS(d, i) {
      var f = tween.call(this, d, i, this.getAttributeNS(name.space, name.local));
      return f === d3_transitionRemove
          ? (this.removeAttributeNS(name.space, name.local), null)
          : f && function(t) { this.setAttributeNS(name.space, name.local, f(t)); };
    }
  
    return this.tween("attr." + nameNS, name.local ? attrTweenNS : attrTween);
  };
  d3_transitionPrototype.style = function(name, value, priority) {
    if (arguments.length < 3) priority = "";
    return this.styleTween(name, d3_transitionTween(value), priority);
  };
  
  d3_transitionPrototype.styleTween = function(name, tween, priority) {
    if (arguments.length < 3) priority = "";
    return this.tween("style." + name, function(d, i) {
      var f = tween.call(this, d, i, window.getComputedStyle(this, null).getPropertyValue(name));
      return f === d3_transitionRemove
          ? (this.style.removeProperty(name), null)
          : f && function(t) { this.style.setProperty(name, f(t), priority); };
    });
  };
  d3_transitionPrototype.text = function(value) {
    return this.tween("text", function(d, i) {
      this.textContent = typeof value === "function"
          ? value.call(this, d, i)
          : value;
    });
  };
  d3_transitionPrototype.remove = function() {
    return this.each("end", function() {
      var p;
      if (!this.__transition__ && (p = this.parentNode)) p.removeChild(this);
    });
  };
  d3_transitionPrototype.delay = function(value) {
    var groups = this;
    return groups.each(typeof value === "function"
        ? function(d, i, j) { groups[j][i].delay = +value.apply(this, arguments); }
        : (value = +value, function(d, i, j) { groups[j][i].delay = value; }));
  };
  d3_transitionPrototype.duration = function(value) {
    var groups = this;
    return groups.each(typeof value === "function"
        ? function(d, i, j) { groups[j][i].duration = +value.apply(this, arguments); }
        : (value = +value, function(d, i, j) { groups[j][i].duration = value; }));
  };
  function d3_transition_each(callback) {
    for (var j = 0, m = this.length; j < m; j++) {
      for (var group = this[j], i = 0, n = group.length; i < n; i++) {
        var node = group[i];
        if (node) callback.call(node = node.node, node.__data__, i, j);
      }
    }
    return this;
  }
  d3_transitionPrototype.transition = function() {
    return this.select(d3_this);
  };
  var d3_timer_queue = null,
      d3_timer_interval, // is an interval (or frame) active?
      d3_timer_timeout; // is a timeout active?
  
  // The timer will continue to fire until callback returns true.
  d3.timer = function(callback, delay, then) {
    var found = false,
        t0,
        t1 = d3_timer_queue;
  
    if (arguments.length < 3) {
      if (arguments.length < 2) delay = 0;
      else if (!isFinite(delay)) return;
      then = Date.now();
    }
  
    // See if the callback's already in the queue.
    while (t1) {
      if (t1.callback === callback) {
        t1.then = then;
        t1.delay = delay;
        found = true;
        break;
      }
      t0 = t1;
      t1 = t1.next;
    }
  
    // Otherwise, add the callback to the queue.
    if (!found) d3_timer_queue = {
      callback: callback,
      then: then,
      delay: delay,
      next: d3_timer_queue
    };
  
    // Start animatin'!
    if (!d3_timer_interval) {
      d3_timer_timeout = clearTimeout(d3_timer_timeout);
      d3_timer_interval = 1;
      d3_timer_frame(d3_timer_step);
    }
  }
  
  function d3_timer_step() {
    var elapsed,
        now = Date.now(),
        t1 = d3_timer_queue;
  
    while (t1) {
      elapsed = now - t1.then;
      if (elapsed >= t1.delay) t1.flush = t1.callback(elapsed);
      t1 = t1.next;
    }
  
    var delay = d3_timer_flush() - now;
    if (delay > 24) {
      if (isFinite(delay)) {
        clearTimeout(d3_timer_timeout);
        d3_timer_timeout = setTimeout(d3_timer_step, delay);
      }
      d3_timer_interval = 0;
    } else {
      d3_timer_interval = 1;
      d3_timer_frame(d3_timer_step);
    }
  }
  
  d3.timer.flush = function() {
    var elapsed,
        now = Date.now(),
        t1 = d3_timer_queue;
  
    while (t1) {
      elapsed = now - t1.then;
      if (!t1.delay) t1.flush = t1.callback(elapsed);
      t1 = t1.next;
    }
  
    d3_timer_flush();
  };
  
  // Flush after callbacks, to avoid concurrent queue modification.
  function d3_timer_flush() {
    var t0 = null,
        t1 = d3_timer_queue,
        then = Infinity;
    while (t1) {
      if (t1.flush) {
        t1 = t0 ? t0.next = t1.next : d3_timer_queue = t1.next;
      } else {
        then = Math.min(then, t1.then + t1.delay);
        t1 = (t0 = t1).next;
      }
    }
    return then;
  }
  
  var d3_timer_frame = window.requestAnimationFrame
      || window.webkitRequestAnimationFrame
      || window.mozRequestAnimationFrame
      || window.oRequestAnimationFrame
      || window.msRequestAnimationFrame
      || function(callback) { setTimeout(callback, 17); };
  function d3_noop() {}
  d3.scale = {};
  
  function d3_scaleExtent(domain) {
    var start = domain[0], stop = domain[domain.length - 1];
    return start < stop ? [start, stop] : [stop, start];
  }
  function d3_scale_nice(domain, nice) {
    var i0 = 0,
        i1 = domain.length - 1,
        x0 = domain[i0],
        x1 = domain[i1],
        dx;
  
    if (x1 < x0) {
      dx = i0; i0 = i1; i1 = dx;
      dx = x0; x0 = x1; x1 = dx;
    }
  
    if (dx = x1 - x0) {
      nice = nice(dx);
      domain[i0] = nice.floor(x0);
      domain[i1] = nice.ceil(x1);
    }
  
    return domain;
  }
  
  function d3_scale_niceDefault() {
    return Math;
  }
  d3.scale.linear = function() {
    return d3_scale_linear([0, 1], [0, 1], d3.interpolate, false);
  };
  
  function d3_scale_linear(domain, range, interpolate, clamp) {
    var output,
        input;
  
    function rescale() {
      var linear = domain.length == 2 ? d3_scale_bilinear : d3_scale_polylinear,
          uninterpolate = clamp ? d3_uninterpolateClamp : d3_uninterpolateNumber;
      output = linear(domain, range, uninterpolate, interpolate);
      input = linear(range, domain, uninterpolate, d3.interpolate);
      return scale;
    }
  
    function scale(x) {
      return output(x);
    }
  
    // Note: requires range is coercible to number!
    scale.invert = function(y) {
      return input(y);
    };
  
    scale.domain = function(x) {
      if (!arguments.length) return domain;
      domain = x.map(Number);
      return rescale();
    };
  
    scale.range = function(x) {
      if (!arguments.length) return range;
      range = x;
      return rescale();
    };
  
    scale.rangeRound = function(x) {
      return scale.range(x).interpolate(d3.interpolateRound);
    };
  
    scale.clamp = function(x) {
      if (!arguments.length) return clamp;
      clamp = x;
      return rescale();
    };
  
    scale.interpolate = function(x) {
      if (!arguments.length) return interpolate;
      interpolate = x;
      return rescale();
    };
  
    scale.ticks = function(m) {
      return d3_scale_linearTicks(domain, m);
    };
  
    scale.tickFormat = function(m) {
      return d3_scale_linearTickFormat(domain, m);
    };
  
    scale.nice = function() {
      d3_scale_nice(domain, d3_scale_linearNice);
      return rescale();
    };
  
    scale.copy = function() {
      return d3_scale_linear(domain, range, interpolate, clamp);
    };
  
    return rescale();
  };
  
  function d3_scale_linearRebind(scale, linear) {
    scale.range = d3.rebind(scale, linear.range);
    scale.rangeRound = d3.rebind(scale, linear.rangeRound);
    scale.interpolate = d3.rebind(scale, linear.interpolate);
    scale.clamp = d3.rebind(scale, linear.clamp);
    return scale;
  }
  
  function d3_scale_linearNice(dx) {
    dx = Math.pow(10, Math.round(Math.log(dx) / Math.LN10) - 1);
    return {
      floor: function(x) { return Math.floor(x / dx) * dx; },
      ceil: function(x) { return Math.ceil(x / dx) * dx; }
    };
  }
  
  // TODO Dates? Ugh.
  function d3_scale_linearTickRange(domain, m) {
    var extent = d3_scaleExtent(domain),
        span = extent[1] - extent[0],
        step = Math.pow(10, Math.floor(Math.log(span / m) / Math.LN10)),
        err = m / span * step;
  
    // Filter ticks to get closer to the desired count.
    if (err <= .15) step *= 10;
    else if (err <= .35) step *= 5;
    else if (err <= .75) step *= 2;
  
    // Round start and stop values to step interval.
    extent[0] = Math.ceil(extent[0] / step) * step;
    extent[1] = Math.floor(extent[1] / step) * step + step * .5; // inclusive
    extent[2] = step;
    return extent;
  }
  
  function d3_scale_linearTicks(domain, m) {
    return d3.range.apply(d3, d3_scale_linearTickRange(domain, m));
  }
  
  function d3_scale_linearTickFormat(domain, m) {
    return d3.format(",." + Math.max(0, -Math.floor(Math.log(d3_scale_linearTickRange(domain, m)[2]) / Math.LN10 + .01)) + "f");
  }
  function d3_scale_bilinear(domain, range, uninterpolate, interpolate) {
    var u = uninterpolate(domain[0], domain[1]),
        i = interpolate(range[0], range[1]);
    return function(x) {
      return i(u(x));
    };
  }
  function d3_scale_polylinear(domain, range, uninterpolate, interpolate) {
    var u = [],
        i = [],
        j = 0,
        n = domain.length;
  
    while (++j < n) {
      u.push(uninterpolate(domain[j - 1], domain[j]));
      i.push(interpolate(range[j - 1], range[j]));
    }
  
    return function(x) {
      var j = d3.bisect(domain, x, 1, domain.length - 1) - 1;
      return i[j](u[j](x));
    };
  }
  d3.scale.log = function() {
    return d3_scale_log(d3.scale.linear(), d3_scale_logp);
  };
  
  function d3_scale_log(linear, log) {
    var pow = log.pow;
  
    function scale(x) {
      return linear(log(x));
    }
  
    scale.invert = function(x) {
      return pow(linear.invert(x));
    };
  
    scale.domain = function(x) {
      if (!arguments.length) return linear.domain().map(pow);
      log = x[0] < 0 ? d3_scale_logn : d3_scale_logp;
      pow = log.pow;
      linear.domain(x.map(log));
      return scale;
    };
  
    scale.nice = function() {
      linear.domain(d3_scale_nice(linear.domain(), d3_scale_niceDefault));
      return scale;
    };
  
    scale.ticks = function() {
      var extent = d3_scaleExtent(linear.domain()),
          ticks = [];
      if (extent.every(isFinite)) {
        var i = Math.floor(extent[0]),
            j = Math.ceil(extent[1]),
            u = Math.round(pow(extent[0])),
            v = Math.round(pow(extent[1]));
        if (log === d3_scale_logn) {
          ticks.push(pow(i));
          for (; i++ < j;) for (var k = 9; k > 0; k--) ticks.push(pow(i) * k);
        } else {
          for (; i < j; i++) for (var k = 1; k < 10; k++) ticks.push(pow(i) * k);
          ticks.push(pow(i));
        }
        for (i = 0; ticks[i] < u; i++) {} // strip small values
        for (j = ticks.length; ticks[j - 1] > v; j--) {} // strip big values
        ticks = ticks.slice(i, j);
      }
      return ticks;
    };
  
    scale.tickFormat = function(n, format) {
      if (arguments.length < 2) format = d3_scale_logFormat;
      if (arguments.length < 1) return format;
      var k = n / scale.ticks().length,
          f = log === d3_scale_logn ? (e = -1e-15, Math.floor) : (e = 1e-15, Math.ceil),
          e;
      return function(d) {
        return d / pow(f(log(d) + e)) < k ? format(d) : "";
      };
    };
  
    scale.copy = function() {
      return d3_scale_log(linear.copy(), log);
    };
  
    return d3_scale_linearRebind(scale, linear);
  };
  
  var d3_scale_logFormat = d3.format("e");
  
  function d3_scale_logp(x) {
    return Math.log(x) / Math.LN10;
  }
  
  function d3_scale_logn(x) {
    return -Math.log(-x) / Math.LN10;
  }
  
  d3_scale_logp.pow = function(x) {
    return Math.pow(10, x);
  };
  
  d3_scale_logn.pow = function(x) {
    return -Math.pow(10, -x);
  };
  d3.scale.pow = function() {
    return d3_scale_pow(d3.scale.linear(), 1);
  };
  
  function d3_scale_pow(linear, exponent) {
    var powp = d3_scale_powPow(exponent),
        powb = d3_scale_powPow(1 / exponent);
  
    function scale(x) {
      return linear(powp(x));
    }
  
    scale.invert = function(x) {
      return powb(linear.invert(x));
    };
  
    scale.domain = function(x) {
      if (!arguments.length) return linear.domain().map(powb);
      linear.domain(x.map(powp));
      return scale;
    };
  
    scale.ticks = function(m) {
      return d3_scale_linearTicks(scale.domain(), m);
    };
  
    scale.tickFormat = function(m) {
      return d3_scale_linearTickFormat(scale.domain(), m);
    };
  
    scale.nice = function() {
      return scale.domain(d3_scale_nice(scale.domain(), d3_scale_linearNice));
    };
  
    scale.exponent = function(x) {
      if (!arguments.length) return exponent;
      var domain = scale.domain();
      powp = d3_scale_powPow(exponent = x);
      powb = d3_scale_powPow(1 / exponent);
      return scale.domain(domain);
    };
  
    scale.copy = function() {
      return d3_scale_pow(linear.copy(), exponent);
    };
  
    return d3_scale_linearRebind(scale, linear);
  };
  
  function d3_scale_powPow(e) {
    return function(x) {
      return x < 0 ? -Math.pow(-x, e) : Math.pow(x, e);
    };
  }
  d3.scale.sqrt = function() {
    return d3.scale.pow().exponent(.5);
  };
  d3.scale.ordinal = function() {
    return d3_scale_ordinal([], {t: "range", x: []});
  };
  
  function d3_scale_ordinal(domain, ranger) {
    var index,
        range,
        rangeBand;
  
    function scale(x) {
      return range[((index[x] || (index[x] = domain.push(x))) - 1) % range.length];
    }
  
    scale.domain = function(x) {
      if (!arguments.length) return domain;
      domain = [];
      index = {};
      var i = -1, n = x.length, xi;
      while (++i < n) if (!index[xi = x[i]]) index[xi] = domain.push(xi);
      return scale[ranger.t](ranger.x, ranger.p);
    };
  
    scale.range = function(x) {
      if (!arguments.length) return range;
      range = x;
      rangeBand = 0;
      ranger = {t: "range", x: x};
      return scale;
    };
  
    scale.rangePoints = function(x, padding) {
      if (arguments.length < 2) padding = 0;
      var start = x[0],
          stop = x[1],
          step = (stop - start) / (domain.length - 1 + padding);
      range = domain.length < 2 ? [(start + stop) / 2] : d3.range(start + step * padding / 2, stop + step / 2, step);
      rangeBand = 0;
      ranger = {t: "rangePoints", x: x, p: padding};
      return scale;
    };
  
    scale.rangeBands = function(x, padding) {
      if (arguments.length < 2) padding = 0;
      var start = x[0],
          stop = x[1],
          step = (stop - start) / (domain.length + padding);
      range = d3.range(start + step * padding, stop, step);
      rangeBand = step * (1 - padding);
      ranger = {t: "rangeBands", x: x, p: padding};
      return scale;
    };
  
    scale.rangeRoundBands = function(x, padding) {
      if (arguments.length < 2) padding = 0;
      var start = x[0],
          stop = x[1],
          step = Math.floor((stop - start) / (domain.length + padding)),
          err = stop - start - (domain.length - padding) * step;
      range = d3.range(start + Math.round(err / 2), stop, step);
      rangeBand = Math.round(step * (1 - padding));
      ranger = {t: "rangeRoundBands", x: x, p: padding};
      return scale;
    };
  
    scale.rangeBand = function() {
      return rangeBand;
    };
  
    scale.copy = function() {
      return d3_scale_ordinal(domain, ranger);
    };
  
    return scale.domain(domain);
  };
  /*
   * This product includes color specifications and designs developed by Cynthia
   * Brewer (http://colorbrewer.org/). See lib/colorbrewer for more information.
   */
  
  d3.scale.category10 = function() {
    return d3.scale.ordinal().range(d3_category10);
  };
  
  d3.scale.category20 = function() {
    return d3.scale.ordinal().range(d3_category20);
  };
  
  d3.scale.category20b = function() {
    return d3.scale.ordinal().range(d3_category20b);
  };
  
  d3.scale.category20c = function() {
    return d3.scale.ordinal().range(d3_category20c);
  };
  
  var d3_category10 = [
    "#1f77b4", "#ff7f0e", "#2ca02c", "#d62728", "#9467bd",
    "#8c564b", "#e377c2", "#7f7f7f", "#bcbd22", "#17becf"
  ];
  
  var d3_category20 = [
    "#1f77b4", "#aec7e8",
    "#ff7f0e", "#ffbb78",
    "#2ca02c", "#98df8a",
    "#d62728", "#ff9896",
    "#9467bd", "#c5b0d5",
    "#8c564b", "#c49c94",
    "#e377c2", "#f7b6d2",
    "#7f7f7f", "#c7c7c7",
    "#bcbd22", "#dbdb8d",
    "#17becf", "#9edae5"
  ];
  
  var d3_category20b = [
    "#393b79", "#5254a3", "#6b6ecf", "#9c9ede",
    "#637939", "#8ca252", "#b5cf6b", "#cedb9c",
    "#8c6d31", "#bd9e39", "#e7ba52", "#e7cb94",
    "#843c39", "#ad494a", "#d6616b", "#e7969c",
    "#7b4173", "#a55194", "#ce6dbd", "#de9ed6"
  ];
  
  var d3_category20c = [
    "#3182bd", "#6baed6", "#9ecae1", "#c6dbef",
    "#e6550d", "#fd8d3c", "#fdae6b", "#fdd0a2",
    "#31a354", "#74c476", "#a1d99b", "#c7e9c0",
    "#756bb1", "#9e9ac8", "#bcbddc", "#dadaeb",
    "#636363", "#969696", "#bdbdbd", "#d9d9d9"
  ];
  d3.scale.quantile = function() {
    return d3_scale_quantile([], []);
  };
  
  function d3_scale_quantile(domain, range) {
    var thresholds;
  
    function rescale() {
      var k = 0,
          n = domain.length,
          q = range.length;
      thresholds = [];
      while (++k < q) thresholds[k - 1] = d3.quantile(domain, k / q);
      return scale;
    }
  
    function scale(x) {
      if (isNaN(x = +x)) return NaN;
      return range[d3.bisect(thresholds, x)];
    }
  
    scale.domain = function(x) {
      if (!arguments.length) return domain;
      domain = x.filter(function(d) { return !isNaN(d); }).sort(d3.ascending);
      return rescale();
    };
  
    scale.range = function(x) {
      if (!arguments.length) return range;
      range = x;
      return rescale();
    };
  
    scale.quantiles = function() {
      return thresholds;
    };
  
    scale.copy = function() {
      return d3_scale_quantile(domain, range); // copy on write!
    };
  
    return rescale();
  };
  d3.scale.quantize = function() {
    return d3_scale_quantize(0, 1, [0, 1]);
  };
  
  function d3_scale_quantize(x0, x1, range) {
    var kx, i;
  
    function scale(x) {
      return range[Math.max(0, Math.min(i, Math.floor(kx * (x - x0))))];
    }
  
    function rescale() {
      kx = range.length / (x1 - x0);
      i = range.length - 1;
      return scale;
    }
  
    scale.domain = function(x) {
      if (!arguments.length) return [x0, x1];
      x0 = +x[0];
      x1 = +x[x.length - 1];
      return rescale();
    };
  
    scale.range = function(x) {
      if (!arguments.length) return range;
      range = x;
      return rescale();
    };
  
    scale.copy = function() {
      return d3_scale_quantize(x0, x1, range); // copy on write
    };
  
    return rescale();
  };
  d3.svg = {};
  d3.svg.arc = function() {
    var innerRadius = d3_svg_arcInnerRadius,
        outerRadius = d3_svg_arcOuterRadius,
        startAngle = d3_svg_arcStartAngle,
        endAngle = d3_svg_arcEndAngle;
  
    function arc() {
      var r0 = innerRadius.apply(this, arguments),
          r1 = outerRadius.apply(this, arguments),
          a0 = startAngle.apply(this, arguments) + d3_svg_arcOffset,
          a1 = endAngle.apply(this, arguments) + d3_svg_arcOffset,
          da = (a1 < a0 && (da = a0, a0 = a1, a1 = da), a1 - a0),
          df = da < Math.PI ? "0" : "1",
          c0 = Math.cos(a0),
          s0 = Math.sin(a0),
          c1 = Math.cos(a1),
          s1 = Math.sin(a1);
      return da >= d3_svg_arcMax
        ? (r0
        ? "M0," + r1
        + "A" + r1 + "," + r1 + " 0 1,1 0," + (-r1)
        + "A" + r1 + "," + r1 + " 0 1,1 0," + r1
        + "M0," + r0
        + "A" + r0 + "," + r0 + " 0 1,0 0," + (-r0)
        + "A" + r0 + "," + r0 + " 0 1,0 0," + r0
        + "Z"
        : "M0," + r1
        + "A" + r1 + "," + r1 + " 0 1,1 0," + (-r1)
        + "A" + r1 + "," + r1 + " 0 1,1 0," + r1
        + "Z")
        : (r0
        ? "M" + r1 * c0 + "," + r1 * s0
        + "A" + r1 + "," + r1 + " 0 " + df + ",1 " + r1 * c1 + "," + r1 * s1
        + "L" + r0 * c1 + "," + r0 * s1
        + "A" + r0 + "," + r0 + " 0 " + df + ",0 " + r0 * c0 + "," + r0 * s0
        + "Z"
        : "M" + r1 * c0 + "," + r1 * s0
        + "A" + r1 + "," + r1 + " 0 " + df + ",1 " + r1 * c1 + "," + r1 * s1
        + "L0,0"
        + "Z");
    }
  
    arc.innerRadius = function(v) {
      if (!arguments.length) return innerRadius;
      innerRadius = d3.functor(v);
      return arc;
    };
  
    arc.outerRadius = function(v) {
      if (!arguments.length) return outerRadius;
      outerRadius = d3.functor(v);
      return arc;
    };
  
    arc.startAngle = function(v) {
      if (!arguments.length) return startAngle;
      startAngle = d3.functor(v);
      return arc;
    };
  
    arc.endAngle = function(v) {
      if (!arguments.length) return endAngle;
      endAngle = d3.functor(v);
      return arc;
    };
  
    arc.centroid = function() {
      var r = (innerRadius.apply(this, arguments)
          + outerRadius.apply(this, arguments)) / 2,
          a = (startAngle.apply(this, arguments)
          + endAngle.apply(this, arguments)) / 2 + d3_svg_arcOffset;
      return [Math.cos(a) * r, Math.sin(a) * r];
    };
  
    return arc;
  };
  
  var d3_svg_arcOffset = -Math.PI / 2,
      d3_svg_arcMax = 2 * Math.PI - 1e-6;
  
  function d3_svg_arcInnerRadius(d) {
    return d.innerRadius;
  }
  
  function d3_svg_arcOuterRadius(d) {
    return d.outerRadius;
  }
  
  function d3_svg_arcStartAngle(d) {
    return d.startAngle;
  }
  
  function d3_svg_arcEndAngle(d) {
    return d.endAngle;
  }
  function d3_svg_line(projection) {
    var x = d3_svg_lineX,
        y = d3_svg_lineY,
        interpolate = "linear",
        interpolator = d3_svg_lineInterpolators[interpolate],
        tension = .7;
  
    function line(d) {
      return d.length < 1 ? null : "M" + interpolator(projection(d3_svg_linePoints(this, d, x, y)), tension);
    }
  
    line.x = function(v) {
      if (!arguments.length) return x;
      x = v;
      return line;
    };
  
    line.y = function(v) {
      if (!arguments.length) return y;
      y = v;
      return line;
    };
  
    line.interpolate = function(v) {
      if (!arguments.length) return interpolate;
      interpolator = d3_svg_lineInterpolators[interpolate = v];
      return line;
    };
  
    line.tension = function(v) {
      if (!arguments.length) return tension;
      tension = v;
      return line;
    };
  
    return line;
  }
  
  d3.svg.line = function() {
    return d3_svg_line(Object);
  };
  
  // Converts the specified array of data into an array of points
  // (x-y tuples), by evaluating the specified `x` and `y` functions on each
  // data point. The `this` context of the evaluated functions is the specified
  // "self" object; each function is passed the current datum and index.
  function d3_svg_linePoints(self, d, x, y) {
    var points = [],
        i = -1,
        n = d.length,
        fx = typeof x === "function",
        fy = typeof y === "function",
        value;
    if (fx && fy) {
      while (++i < n) points.push([
        x.call(self, value = d[i], i),
        y.call(self, value, i)
      ]);
    } else if (fx) {
      while (++i < n) points.push([x.call(self, d[i], i), y]);
    } else if (fy) {
      while (++i < n) points.push([x, y.call(self, d[i], i)]);
    } else {
      while (++i < n) points.push([x, y]);
    }
    return points;
  }
  
  // The default `x` property, which references d[0].
  function d3_svg_lineX(d) {
    return d[0];
  }
  
  // The default `y` property, which references d[1].
  function d3_svg_lineY(d) {
    return d[1];
  }
  
  // The various interpolators supported by the `line` class.
  var d3_svg_lineInterpolators = {
    "linear": d3_svg_lineLinear,
    "step-before": d3_svg_lineStepBefore,
    "step-after": d3_svg_lineStepAfter,
    "basis": d3_svg_lineBasis,
    "basis-open": d3_svg_lineBasisOpen,
    "basis-closed": d3_svg_lineBasisClosed,
    "bundle": d3_svg_lineBundle,
    "cardinal": d3_svg_lineCardinal,
    "cardinal-open": d3_svg_lineCardinalOpen,
    "cardinal-closed": d3_svg_lineCardinalClosed,
    "monotone": d3_svg_lineMonotone
  };
  
  // Linear interpolation; generates "L" commands.
  function d3_svg_lineLinear(points) {
    var i = 0,
        n = points.length,
        p = points[0],
        path = [p[0], ",", p[1]];
    while (++i < n) path.push("L", (p = points[i])[0], ",", p[1]);
    return path.join("");
  }
  
  // Step interpolation; generates "H" and "V" commands.
  function d3_svg_lineStepBefore(points) {
    var i = 0,
        n = points.length,
        p = points[0],
        path = [p[0], ",", p[1]];
    while (++i < n) path.push("V", (p = points[i])[1], "H", p[0]);
    return path.join("");
  }
  
  // Step interpolation; generates "H" and "V" commands.
  function d3_svg_lineStepAfter(points) {
    var i = 0,
        n = points.length,
        p = points[0],
        path = [p[0], ",", p[1]];
    while (++i < n) path.push("H", (p = points[i])[0], "V", p[1]);
    return path.join("");
  }
  
  // Open cardinal spline interpolation; generates "C" commands.
  function d3_svg_lineCardinalOpen(points, tension) {
    return points.length < 4
        ? d3_svg_lineLinear(points)
        : points[1] + d3_svg_lineHermite(points.slice(1, points.length - 1),
          d3_svg_lineCardinalTangents(points, tension));
  }
  
  // Closed cardinal spline interpolation; generates "C" commands.
  function d3_svg_lineCardinalClosed(points, tension) {
    return points.length < 3
        ? d3_svg_lineLinear(points)
        : points[0] + d3_svg_lineHermite((points.push(points[0]), points),
          d3_svg_lineCardinalTangents([points[points.length - 2]]
          .concat(points, [points[1]]), tension));
  }
  
  // Cardinal spline interpolation; generates "C" commands.
  function d3_svg_lineCardinal(points, tension, closed) {
    return points.length < 3
        ? d3_svg_lineLinear(points)
        : points[0] + d3_svg_lineHermite(points,
          d3_svg_lineCardinalTangents(points, tension));
  }
  
  // Hermite spline construction; generates "C" commands.
  function d3_svg_lineHermite(points, tangents) {
    if (tangents.length < 1
        || (points.length != tangents.length
        && points.length != tangents.length + 2)) {
      return d3_svg_lineLinear(points);
    }
  
    var quad = points.length != tangents.length,
        path = "",
        p0 = points[0],
        p = points[1],
        t0 = tangents[0],
        t = t0,
        pi = 1;
  
    if (quad) {
      path += "Q" + (p[0] - t0[0] * 2 / 3) + "," + (p[1] - t0[1] * 2 / 3)
          + "," + p[0] + "," + p[1];
      p0 = points[1];
      pi = 2;
    }
  
    if (tangents.length > 1) {
      t = tangents[1];
      p = points[pi];
      pi++;
      path += "C" + (p0[0] + t0[0]) + "," + (p0[1] + t0[1])
          + "," + (p[0] - t[0]) + "," + (p[1] - t[1])
          + "," + p[0] + "," + p[1];
      for (var i = 2; i < tangents.length; i++, pi++) {
        p = points[pi];
        t = tangents[i];
        path += "S" + (p[0] - t[0]) + "," + (p[1] - t[1])
            + "," + p[0] + "," + p[1];
      }
    }
  
    if (quad) {
      var lp = points[pi];
      path += "Q" + (p[0] + t[0] * 2 / 3) + "," + (p[1] + t[1] * 2 / 3)
          + "," + lp[0] + "," + lp[1];
    }
  
    return path;
  }
  
  // Generates tangents for a cardinal spline.
  function d3_svg_lineCardinalTangents(points, tension) {
    var tangents = [],
        a = (1 - tension) / 2,
        p0,
        p1 = points[0],
        p2 = points[1],
        i = 1,
        n = points.length;
    while (++i < n) {
      p0 = p1;
      p1 = p2;
      p2 = points[i];
      tangents.push([a * (p2[0] - p0[0]), a * (p2[1] - p0[1])]);
    }
    return tangents;
  }
  
  // B-spline interpolation; generates "C" commands.
  function d3_svg_lineBasis(points) {
    if (points.length < 3) return d3_svg_lineLinear(points);
    var i = 1,
        n = points.length,
        pi = points[0],
        x0 = pi[0],
        y0 = pi[1],
        px = [x0, x0, x0, (pi = points[1])[0]],
        py = [y0, y0, y0, pi[1]],
        path = [x0, ",", y0];
    d3_svg_lineBasisBezier(path, px, py);
    while (++i < n) {
      pi = points[i];
      px.shift(); px.push(pi[0]);
      py.shift(); py.push(pi[1]);
      d3_svg_lineBasisBezier(path, px, py);
    }
    i = -1;
    while (++i < 2) {
      px.shift(); px.push(pi[0]);
      py.shift(); py.push(pi[1]);
      d3_svg_lineBasisBezier(path, px, py);
    }
    return path.join("");
  }
  
  // Open B-spline interpolation; generates "C" commands.
  function d3_svg_lineBasisOpen(points) {
    if (points.length < 4) return d3_svg_lineLinear(points);
    var path = [],
        i = -1,
        n = points.length,
        pi,
        px = [0],
        py = [0];
    while (++i < 3) {
      pi = points[i];
      px.push(pi[0]);
      py.push(pi[1]);
    }
    path.push(d3_svg_lineDot4(d3_svg_lineBasisBezier3, px)
      + "," + d3_svg_lineDot4(d3_svg_lineBasisBezier3, py));
    --i; while (++i < n) {
      pi = points[i];
      px.shift(); px.push(pi[0]);
      py.shift(); py.push(pi[1]);
      d3_svg_lineBasisBezier(path, px, py);
    }
    return path.join("");
  }
  
  // Closed B-spline interpolation; generates "C" commands.
  function d3_svg_lineBasisClosed(points) {
    var path,
        i = -1,
        n = points.length,
        m = n + 4,
        pi,
        px = [],
        py = [];
    while (++i < 4) {
      pi = points[i % n];
      px.push(pi[0]);
      py.push(pi[1]);
    }
    path = [
      d3_svg_lineDot4(d3_svg_lineBasisBezier3, px), ",",
      d3_svg_lineDot4(d3_svg_lineBasisBezier3, py)
    ];
    --i; while (++i < m) {
      pi = points[i % n];
      px.shift(); px.push(pi[0]);
      py.shift(); py.push(pi[1]);
      d3_svg_lineBasisBezier(path, px, py);
    }
    return path.join("");
  }
  
  function d3_svg_lineBundle(points, tension) {
    var n = points.length - 1,
        x0 = points[0][0],
        y0 = points[0][1],
        dx = points[n][0] - x0,
        dy = points[n][1] - y0,
        i = -1,
        p,
        t;
    while (++i <= n) {
      p = points[i];
      t = i / n;
      p[0] = tension * p[0] + (1 - tension) * (x0 + t * dx);
      p[1] = tension * p[1] + (1 - tension) * (y0 + t * dy);
    }
    return d3_svg_lineBasis(points);
  }
  
  // Returns the dot product of the given four-element vectors.
  function d3_svg_lineDot4(a, b) {
    return a[0] * b[0] + a[1] * b[1] + a[2] * b[2] + a[3] * b[3];
  }
  
  // Matrix to transform basis (b-spline) control points to bezier
  // control points. Derived from FvD 11.2.8.
  var d3_svg_lineBasisBezier1 = [0, 2/3, 1/3, 0],
      d3_svg_lineBasisBezier2 = [0, 1/3, 2/3, 0],
      d3_svg_lineBasisBezier3 = [0, 1/6, 2/3, 1/6];
  
  // Pushes a "C" Bézier curve onto the specified path array, given the
  // two specified four-element arrays which define the control points.
  function d3_svg_lineBasisBezier(path, x, y) {
    path.push(
        "C", d3_svg_lineDot4(d3_svg_lineBasisBezier1, x),
        ",", d3_svg_lineDot4(d3_svg_lineBasisBezier1, y),
        ",", d3_svg_lineDot4(d3_svg_lineBasisBezier2, x),
        ",", d3_svg_lineDot4(d3_svg_lineBasisBezier2, y),
        ",", d3_svg_lineDot4(d3_svg_lineBasisBezier3, x),
        ",", d3_svg_lineDot4(d3_svg_lineBasisBezier3, y));
  }
  
  // Computes the slope from points p0 to p1.
  function d3_svg_lineSlope(p0, p1) {
    return (p1[1] - p0[1]) / (p1[0] - p0[0]);
  }
  
  // Compute three-point differences for the given points.
  // http://en.wikipedia.org/wiki/Cubic_Hermite_spline#Finite_difference
  function d3_svg_lineFiniteDifferences(points) {
    var i = 0,
        j = points.length - 1,
        m = [],
        p0 = points[0],
        p1 = points[1],
        d = m[0] = d3_svg_lineSlope(p0, p1);
    while (++i < j) {
      m[i] = d + (d = d3_svg_lineSlope(p0 = p1, p1 = points[i + 1]));
    }
    m[i] = d;
    return m;
  }
  
  // Interpolates the given points using Fritsch-Carlson Monotone cubic Hermite
  // interpolation. Returns an array of tangent vectors. For details, see
  // http://en.wikipedia.org/wiki/Monotone_cubic_interpolation
  function d3_svg_lineMonotoneTangents(points) {
    var tangents = [],
        d,
        a,
        b,
        s,
        m = d3_svg_lineFiniteDifferences(points),
        i = -1,
        j = points.length - 1;
  
    // The first two steps are done by computing finite-differences:
    // 1. Compute the slopes of the secant lines between successive points.
    // 2. Initialize the tangents at every point as the average of the secants.
  
    // Then, for each segment…
    while (++i < j) {
      d = d3_svg_lineSlope(points[i], points[i + 1]);
  
      // 3. If two successive yk = y{k + 1} are equal (i.e., d is zero), then set
      // mk = m{k + 1} = 0 as the spline connecting these points must be flat to
      // preserve monotonicity. Ignore step 4 and 5 for those k.
  
      if (Math.abs(d) < 1e-6) {
        m[i] = m[i + 1] = 0;
      } else {
        // 4. Let ak = mk / dk and bk = m{k + 1} / dk.
        a = m[i] / d;
        b = m[i + 1] / d;
  
        // 5. Prevent overshoot and ensure monotonicity by restricting the
        // magnitude of vector <ak, bk> to a circle of radius 3.
        s = a * a + b * b;
        if (s > 9) {
          s = d * 3 / Math.sqrt(s);
          m[i] = s * a;
          m[i + 1] = s * b;
        }
      }
    }
  
    // Compute the normalized tangent vector from the slopes. Note that if x is
    // not monotonic, it's possible that the slope will be infinite, so we protect
    // against NaN by setting the coordinate to zero.
    i = -1; while (++i <= j) {
      s = (points[Math.min(j, i + 1)][0] - points[Math.max(0, i - 1)][0])
        / (6 * (1 + m[i] * m[i]));
      tangents.push([s || 0, m[i] * s || 0]);
    }
  
    return tangents;
  }
  
  function d3_svg_lineMonotone(points) {
    return points.length < 3
        ? d3_svg_lineLinear(points)
        : points[0] +
          d3_svg_lineHermite(points, d3_svg_lineMonotoneTangents(points));
  }
  d3.svg.line.radial = function() {
    var line = d3_svg_line(d3_svg_lineRadial);
    line.radius = line.x, delete line.x;
    line.angle = line.y, delete line.y;
    return line;
  };
  
  function d3_svg_lineRadial(points) {
    var point,
        i = -1,
        n = points.length,
        r,
        a;
    while (++i < n) {
      point = points[i];
      r = point[0];
      a = point[1] + d3_svg_arcOffset;
      point[0] = r * Math.cos(a);
      point[1] = r * Math.sin(a);
    }
    return points;
  }
  function d3_svg_area(projection) {
    var x0 = d3_svg_lineX,
        x1 = d3_svg_lineX,
        y0 = 0,
        y1 = d3_svg_lineY,
        interpolate,
        i0,
        i1,
        tension = .7;
  
    function area(d) {
      if (d.length < 1) return null;
      var points0 = d3_svg_linePoints(this, d, x0, y0),
          points1 = d3_svg_linePoints(this, d, x0 === x1 ? d3_svg_areaX(points0) : x1, y0 === y1 ? d3_svg_areaY(points0) : y1);
      return "M" + i0(projection(points1), tension)
           + "L" + i1(projection(points0.reverse()), tension)
           + "Z";
    }
  
    area.x = function(x) {
      if (!arguments.length) return x1;
      x0 = x1 = x;
      return area;
    };
  
    area.x0 = function(x) {
      if (!arguments.length) return x0;
      x0 = x;
      return area;
    };
  
    area.x1 = function(x) {
      if (!arguments.length) return x1;
      x1 = x;
      return area;
    };
  
    area.y = function(y) {
      if (!arguments.length) return y1;
      y0 = y1 = y;
      return area;
    };
  
    area.y0 = function(y) {
      if (!arguments.length) return y0;
      y0 = y;
      return area;
    };
  
    area.y1 = function(y) {
      if (!arguments.length) return y1;
      y1 = y;
      return area;
    };
  
    area.interpolate = function(x) {
      if (!arguments.length) return interpolate;
      i0 = d3_svg_lineInterpolators[interpolate = x];
      i1 = i0.reverse || i0;
      return area;
    };
  
    area.tension = function(x) {
      if (!arguments.length) return tension;
      tension = x;
      return area;
    };
  
    return area.interpolate("linear");
  }
  
  d3_svg_lineStepBefore.reverse = d3_svg_lineStepAfter;
  d3_svg_lineStepAfter.reverse = d3_svg_lineStepBefore;
  
  d3.svg.area = function() {
    return d3_svg_area(Object);
  };
  
  function d3_svg_areaX(points) {
    return function(d, i) {
      return points[i][0];
    };
  }
  
  function d3_svg_areaY(points) {
    return function(d, i) {
      return points[i][1];
    };
  }
  d3.svg.area.radial = function() {
    var area = d3_svg_area(d3_svg_lineRadial);
    area.radius = area.x, delete area.x;
    area.innerRadius = area.x0, delete area.x0;
    area.outerRadius = area.x1, delete area.x1;
    area.angle = area.y, delete area.y;
    area.startAngle = area.y0, delete area.y0;
    area.endAngle = area.y1, delete area.y1;
    return area;
  };
  d3.svg.chord = function() {
    var source = d3_svg_chordSource,
        target = d3_svg_chordTarget,
        radius = d3_svg_chordRadius,
        startAngle = d3_svg_arcStartAngle,
        endAngle = d3_svg_arcEndAngle;
  
    // TODO Allow control point to be customized.
  
    function chord(d, i) {
      var s = subgroup(this, source, d, i),
          t = subgroup(this, target, d, i);
      return "M" + s.p0
        + arc(s.r, s.p1) + (equals(s, t)
        ? curve(s.r, s.p1, s.r, s.p0)
        : curve(s.r, s.p1, t.r, t.p0)
        + arc(t.r, t.p1)
        + curve(t.r, t.p1, s.r, s.p0))
        + "Z";
    }
  
    function subgroup(self, f, d, i) {
      var subgroup = f.call(self, d, i),
          r = radius.call(self, subgroup, i),
          a0 = startAngle.call(self, subgroup, i) + d3_svg_arcOffset,
          a1 = endAngle.call(self, subgroup, i) + d3_svg_arcOffset;
      return {
        r: r,
        a0: a0,
        a1: a1,
        p0: [r * Math.cos(a0), r * Math.sin(a0)],
        p1: [r * Math.cos(a1), r * Math.sin(a1)]
      };
    }
  
    function equals(a, b) {
      return a.a0 == b.a0 && a.a1 == b.a1;
    }
  
    function arc(r, p) {
      return "A" + r + "," + r + " 0 0,1 " + p;
    }
  
    function curve(r0, p0, r1, p1) {
      return "Q 0,0 " + p1;
    }
  
    chord.radius = function(v) {
      if (!arguments.length) return radius;
      radius = d3.functor(v);
      return chord;
    };
  
    chord.source = function(v) {
      if (!arguments.length) return source;
      source = d3.functor(v);
      return chord;
    };
  
    chord.target = function(v) {
      if (!arguments.length) return target;
      target = d3.functor(v);
      return chord;
    };
  
    chord.startAngle = function(v) {
      if (!arguments.length) return startAngle;
      startAngle = d3.functor(v);
      return chord;
    };
  
    chord.endAngle = function(v) {
      if (!arguments.length) return endAngle;
      endAngle = d3.functor(v);
      return chord;
    };
  
    return chord;
  };
  
  function d3_svg_chordSource(d) {
    return d.source;
  }
  
  function d3_svg_chordTarget(d) {
    return d.target;
  }
  
  function d3_svg_chordRadius(d) {
    return d.radius;
  }
  
  function d3_svg_chordStartAngle(d) {
    return d.startAngle;
  }
  
  function d3_svg_chordEndAngle(d) {
    return d.endAngle;
  }
  d3.svg.diagonal = function() {
    var source = d3_svg_chordSource,
        target = d3_svg_chordTarget,
        projection = d3_svg_diagonalProjection;
  
    function diagonal(d, i) {
      var p0 = source.call(this, d, i),
          p3 = target.call(this, d, i),
          m = (p0.y + p3.y) / 2,
          p = [p0, {x: p0.x, y: m}, {x: p3.x, y: m}, p3];
      p = p.map(projection);
      return "M" + p[0] + "C" + p[1] + " " + p[2] + " " + p[3];
    }
  
    diagonal.source = function(x) {
      if (!arguments.length) return source;
      source = d3.functor(x);
      return diagonal;
    };
  
    diagonal.target = function(x) {
      if (!arguments.length) return target;
      target = d3.functor(x);
      return diagonal;
    };
  
    diagonal.projection = function(x) {
      if (!arguments.length) return projection;
      projection = x;
      return diagonal;
    };
  
    return diagonal;
  };
  
  function d3_svg_diagonalProjection(d) {
    return [d.x, d.y];
  }
  d3.svg.diagonal.radial = function() {
    var diagonal = d3.svg.diagonal(),
        projection = d3_svg_diagonalProjection,
        projection_ = diagonal.projection;
  
    diagonal.projection = function(x) {
      return arguments.length
          ? projection_(d3_svg_diagonalRadialProjection(projection = x))
          : projection;
    };
  
    return diagonal;
  };
  
  function d3_svg_diagonalRadialProjection(projection) {
    return function() {
      var d = projection.apply(this, arguments),
          r = d[0],
          a = d[1] + d3_svg_arcOffset;
      return [r * Math.cos(a), r * Math.sin(a)];
    };
  }
  d3.svg.mouse = function(container) {
    return d3_svg_mousePoint(container, d3.event);
  };
  
  // https://bugs.webkit.org/show_bug.cgi?id=44083
  var d3_mouse_bug44083 = /WebKit/.test(navigator.userAgent) ? -1 : 0;
  
  function d3_svg_mousePoint(container, e) {
    var point = (container.ownerSVGElement || container).createSVGPoint();
    if ((d3_mouse_bug44083 < 0) && (window.scrollX || window.scrollY)) {
      var svg = d3.select(document.body)
        .append("svg:svg")
          .style("position", "absolute")
          .style("top", 0)
          .style("left", 0);
      var ctm = svg[0][0].getScreenCTM();
      d3_mouse_bug44083 = !(ctm.f || ctm.e);
      svg.remove();
    }
    if (d3_mouse_bug44083) {
      point.x = e.pageX;
      point.y = e.pageY;
    } else {
      point.x = e.clientX;
      point.y = e.clientY;
    }
    point = point.matrixTransform(container.getScreenCTM().inverse());
    return [point.x, point.y];
  };
  d3.svg.touches = function(container) {
    var touches = d3.event.touches;
    return touches ? d3_array(touches).map(function(touch) {
      var point = d3_svg_mousePoint(container, touch);
      point.identifier = touch.identifier;
      return point;
    }) : [];
  };
  d3.svg.symbol = function() {
    var type = d3_svg_symbolType,
        size = d3_svg_symbolSize;
  
    function symbol(d, i) {
      return (d3_svg_symbols[type.call(this, d, i)]
          || d3_svg_symbols.circle)
          (size.call(this, d, i));
    }
  
    symbol.type = function(x) {
      if (!arguments.length) return type;
      type = d3.functor(x);
      return symbol;
    };
  
    // size of symbol in square pixels
    symbol.size = function(x) {
      if (!arguments.length) return size;
      size = d3.functor(x);
      return symbol;
    };
  
    return symbol;
  };
  
  function d3_svg_symbolSize() {
    return 64;
  }
  
  function d3_svg_symbolType() {
    return "circle";
  }
  
  // TODO cross-diagonal?
  var d3_svg_symbols = {
    "circle": function(size) {
      var r = Math.sqrt(size / Math.PI);
      return "M0," + r
          + "A" + r + "," + r + " 0 1,1 0," + (-r)
          + "A" + r + "," + r + " 0 1,1 0," + r
          + "Z";
    },
    "cross": function(size) {
      var r = Math.sqrt(size / 5) / 2;
      return "M" + -3 * r + "," + -r
          + "H" + -r
          + "V" + -3 * r
          + "H" + r
          + "V" + -r
          + "H" + 3 * r
          + "V" + r
          + "H" + r
          + "V" + 3 * r
          + "H" + -r
          + "V" + r
          + "H" + -3 * r
          + "Z";
    },
    "diamond": function(size) {
      var ry = Math.sqrt(size / (2 * d3_svg_symbolTan30)),
          rx = ry * d3_svg_symbolTan30;
      return "M0," + -ry
          + "L" + rx + ",0"
          + " 0," + ry
          + " " + -rx + ",0"
          + "Z";
    },
    "square": function(size) {
      var r = Math.sqrt(size) / 2;
      return "M" + -r + "," + -r
          + "L" + r + "," + -r
          + " " + r + "," + r
          + " " + -r + "," + r
          + "Z";
    },
    "triangle-down": function(size) {
      var rx = Math.sqrt(size / d3_svg_symbolSqrt3),
          ry = rx * d3_svg_symbolSqrt3 / 2;
      return "M0," + ry
          + "L" + rx +"," + -ry
          + " " + -rx + "," + -ry
          + "Z";
    },
    "triangle-up": function(size) {
      var rx = Math.sqrt(size / d3_svg_symbolSqrt3),
          ry = rx * d3_svg_symbolSqrt3 / 2;
      return "M0," + -ry
          + "L" + rx +"," + ry
          + " " + -rx + "," + ry
          + "Z";
    }
  };
  
  d3.svg.symbolTypes = d3.keys(d3_svg_symbols);
  
  var d3_svg_symbolSqrt3 = Math.sqrt(3),
      d3_svg_symbolTan30 = Math.tan(30 * Math.PI / 180);
  d3.svg.axis = function() {
    var scale = d3.scale.linear(),
        orient = "bottom",
        tickMajorSize = 6,
        tickMinorSize = 6,
        tickEndSize = 6,
        tickPadding = 3,
        tickArguments_ = [10],
        tickFormat_,
        tickSubdivide = 0;
  
    function axis(selection) {
      selection.each(function(d, i, j) {
        var g = d3.select(this);
  
        // If selection is a transition, create subtransitions.
        var transition = selection.delay ? function(o) {
          var id = d3_transitionInheritId;
          try {
            d3_transitionInheritId = selection.id;
            return o.transition()
                .delay(selection[j][i].delay)
                .duration(selection[j][i].duration)
                .ease(selection.ease());
          } finally {
            d3_transitionInheritId = id;
          }
        } : Object;
  
        // Ticks.
        var ticks = scale.ticks.apply(scale, tickArguments_),
            tickFormat = tickFormat_ == null ? scale.tickFormat.apply(scale, tickArguments_) : tickFormat_;
  
        // Minor ticks.
        var subticks = d3_svg_axisSubdivide(scale, ticks, tickSubdivide),
            subtick = g.selectAll(".minor").data(subticks, String),
            subtickEnter = subtick.enter().insert("svg:line", "g").attr("class", "tick minor").style("opacity", 1e-6),
            subtickExit = transition(subtick.exit()).style("opacity", 1e-6).remove(),
            subtickUpdate = transition(subtick).style("opacity", 1);
  
        // Major ticks.
        var tick = g.selectAll("g").data(ticks, String),
            tickEnter = tick.enter().insert("svg:g", "path").style("opacity", 1e-6),
            tickExit = transition(tick.exit()).style("opacity", 1e-6).remove(),
            tickUpdate = transition(tick).style("opacity", 1),
            tickTransform;
  
        // Domain.
        var range = d3_scaleExtent(scale.range()),
            path = g.selectAll(".domain").data([0]),
            pathEnter = path.enter().append("svg:path").attr("class", "domain"),
            pathUpdate = transition(path);
  
        // Stash the new scale and grab the old scale.
        var scale0 = this.__chart__ || scale;
        this.__chart__ = scale.copy();
  
        tickEnter.append("svg:line").attr("class", "tick");
        tickEnter.append("svg:text");
        tickUpdate.select("text").text(tickFormat);
  
        switch (orient) {
          case "bottom": {
            tickTransform = d3_svg_axisX;
            subtickUpdate.attr("x2", 0).attr("y2", tickMinorSize);
            tickUpdate.select("line").attr("x2", 0).attr("y2", tickMajorSize);
            tickUpdate.select("text").attr("x", 0).attr("y", Math.max(tickMajorSize, 0) + tickPadding).attr("dy", ".71em").attr("text-anchor", "middle");
            pathUpdate.attr("d", "M" + range[0] + "," + tickEndSize + "V0H" + range[1] + "V" + tickEndSize);
            break;
          }
          case "top": {
            tickTransform = d3_svg_axisX;
            subtickUpdate.attr("x2", 0).attr("y2", -tickMinorSize);
            tickUpdate.select("line").attr("x2", 0).attr("y2", -tickMajorSize);
            tickUpdate.select("text").attr("x", 0).attr("y", -(Math.max(tickMajorSize, 0) + tickPadding)).attr("dy", "0em").attr("text-anchor", "middle");
            pathUpdate.attr("d", "M" + range[0] + "," + -tickEndSize + "V0H" + range[1] + "V" + -tickEndSize);
            break;
          }
          case "left": {
            tickTransform = d3_svg_axisY;
            subtickUpdate.attr("x2", -tickMinorSize).attr("y2", 0);
            tickUpdate.select("line").attr("x2", -tickMajorSize).attr("y2", 0);
            tickUpdate.select("text").attr("x", -(Math.max(tickMajorSize, 0) + tickPadding)).attr("y", 0).attr("dy", ".32em").attr("text-anchor", "end");
            pathUpdate.attr("d", "M" + -tickEndSize + "," + range[0] + "H0V" + range[1] + "H" + -tickEndSize);
            break;
          }
          case "right": {
            tickTransform = d3_svg_axisY;
            subtickUpdate.attr("x2", tickMinorSize).attr("y2", 0);
            tickUpdate.select("line").attr("x2", tickMajorSize).attr("y2", 0);
            tickUpdate.select("text").attr("x", Math.max(tickMajorSize, 0) + tickPadding).attr("y", 0).attr("dy", ".32em").attr("text-anchor", "start");
            pathUpdate.attr("d", "M" + tickEndSize + "," + range[0] + "H0V" + range[1] + "H" + tickEndSize);
            break;
          }
        }
  
        tickEnter.call(tickTransform, scale0);
        tickUpdate.call(tickTransform, scale);
        tickExit.call(tickTransform, scale);
  
        subtickEnter.call(tickTransform, scale0);
        subtickUpdate.call(tickTransform, scale);
        subtickExit.call(tickTransform, scale);
      });
    }
  
    axis.scale = function(x) {
      if (!arguments.length) return scale;
      scale = x;
      return axis;
    };
  
    axis.orient = function(x) {
      if (!arguments.length) return orient;
      orient = x;
      return axis;
    };
  
    axis.ticks = function() {
      if (!arguments.length) return tickArguments_;
      tickArguments_ = arguments;
      return axis;
    };
  
    axis.tickFormat = function(x) {
      if (!arguments.length) return tickFormat_;
      tickFormat_ = x;
      return axis;
    };
  
    axis.tickSize = function(x, y, z) {
      if (!arguments.length) return tickMajorSize;
      var n = arguments.length - 1;
      tickMajorSize = +x;
      tickMinorSize = n > 1 ? +y : tickMajorSize;
      tickEndSize = n > 0 ? +arguments[n] : tickMajorSize;
      return axis;
    };
  
    axis.tickPadding = function(x) {
      if (!arguments.length) return tickPadding;
      tickPadding = +x;
      return axis;
    };
  
    axis.tickSubdivide = function(x) {
      if (!arguments.length) return tickSubdivide;
      tickSubdivide = +x;
      return axis;
    };
  
    return axis;
  };
  
  function d3_svg_axisX(selection, x) {
    selection.attr("transform", function(d) { return "translate(" + x(d) + ",0)"; });
  }
  
  function d3_svg_axisY(selection, y) {
    selection.attr("transform", function(d) { return "translate(0," + y(d) + ")"; });
  }
  
  function d3_svg_axisSubdivide(scale, ticks, m) {
    subticks = [];
    if (m && ticks.length > 1) {
      var extent = d3_scaleExtent(scale.domain()),
          subticks,
          i = -1,
          n = ticks.length,
          d = (ticks[1] - ticks[0]) / ++m,
          j,
          v;
      while (++i < n) {
        for (j = m; --j > 0;) {
          if ((v = +ticks[i] - j * d) >= extent[0]) {
            subticks.push(v);
          }
        }
      }
      for (--i, j = 0; ++j < m && (v = +ticks[i] + j * d) < extent[1];) {
        subticks.push(v);
      }
    }
    return subticks;
  }
  d3.behavior = {};
  d3.behavior.drag = function() {
    var event = d3.dispatch("drag", "dragstart", "dragend");
  
    function drag() {
      this
          .on("mousedown.drag", mousedown)
          .on("touchstart.drag", mousedown);
  
      d3.select(window)
          .on("mousemove.drag", d3_behavior_dragMove)
          .on("touchmove.drag", d3_behavior_dragMove)
          .on("mouseup.drag", d3_behavior_dragUp, true)
          .on("touchend.drag", d3_behavior_dragUp, true)
          .on("click.drag", d3_behavior_dragClick, true);
    }
  
    // snapshot the local context for subsequent dispatch
    function start() {
      d3_behavior_dragEvent = event;
      d3_behavior_dragEventTarget = d3.event.target;
      d3_behavior_dragOffset = d3_behavior_dragPoint((d3_behavior_dragTarget = this).parentNode);
      d3_behavior_dragMoved = 0;
      d3_behavior_dragArguments = arguments;
    }
  
    function mousedown() {
      start.apply(this, arguments);
      d3_behavior_dragDispatch("dragstart");
    }
  
    drag.on = function(type, listener) {
      event[type].add(listener);
      return drag;
    };
  
    return drag;
  };
  
  var d3_behavior_dragEvent,
      d3_behavior_dragEventTarget,
      d3_behavior_dragTarget,
      d3_behavior_dragArguments,
      d3_behavior_dragOffset,
      d3_behavior_dragMoved,
      d3_behavior_dragStopClick;
  
  function d3_behavior_dragDispatch(type) {
    var o = d3.event, p = d3_behavior_dragTarget.parentNode, dx = 0, dy = 0;
  
    if (p) {
      p = d3_behavior_dragPoint(p);
      dx = p[0] - d3_behavior_dragOffset[0];
      dy = p[1] - d3_behavior_dragOffset[1];
      d3_behavior_dragOffset = p;
      d3_behavior_dragMoved |= dx | dy;
    }
  
    try {
      d3.event = {dx: dx, dy: dy};
      d3_behavior_dragEvent[type].dispatch.apply(d3_behavior_dragTarget, d3_behavior_dragArguments);
    } finally {
      d3.event = o;
    }
  
    o.preventDefault();
  }
  
  function d3_behavior_dragPoint(container) {
    return d3.event.touches
        ? d3.svg.touches(container)[0]
        : d3.svg.mouse(container);
  }
  
  function d3_behavior_dragMove() {
    if (!d3_behavior_dragTarget) return;
    var parent = d3_behavior_dragTarget.parentNode;
  
    // O NOES! The drag element was removed from the DOM.
    if (!parent) return d3_behavior_dragUp();
  
    d3_behavior_dragDispatch("drag");
    d3_behavior_dragCancel();
  }
  
  function d3_behavior_dragUp() {
    if (!d3_behavior_dragTarget) return;
    d3_behavior_dragDispatch("dragend");
    d3_behavior_dragTarget = null;
  
    // If the node was moved, prevent the mouseup from propagating.
    // Also prevent the subsequent click from propagating (e.g., for anchors).
    if (d3_behavior_dragMoved && d3_behavior_dragEventTarget === d3.event.target) {
      d3_behavior_dragStopClick = true;
      d3_behavior_dragCancel();
    }
  }
  
  function d3_behavior_dragClick() {
    if (d3_behavior_dragStopClick && d3_behavior_dragEventTarget === d3.event.target) {
      d3_behavior_dragCancel();
      d3_behavior_dragStopClick = false;
      d3_behavior_dragEventTarget = null;
    }
  }
  
  function d3_behavior_dragCancel() {
    d3.event.stopPropagation();
    d3.event.preventDefault();
  }
  // TODO unbind zoom behavior?
  // TODO unbind listener?
  d3.behavior.zoom = function() {
    var xyz = [0, 0, 0],
        event = d3.dispatch("zoom");
  
    function zoom() {
      this
          .on("mousedown.zoom", mousedown)
          .on("mousewheel.zoom", mousewheel)
          .on("DOMMouseScroll.zoom", mousewheel)
          .on("dblclick.zoom", dblclick)
          .on("touchstart.zoom", touchstart);
  
      d3.select(window)
          .on("mousemove.zoom", d3_behavior_zoomMousemove)
          .on("mouseup.zoom", d3_behavior_zoomMouseup)
          .on("touchmove.zoom", d3_behavior_zoomTouchmove)
          .on("touchend.zoom", d3_behavior_zoomTouchup)
          .on("click.zoom", d3_behavior_zoomClick, true);
    }
  
    // snapshot the local context for subsequent dispatch
    function start() {
      d3_behavior_zoomXyz = xyz;
      d3_behavior_zoomDispatch = event.zoom.dispatch;
      d3_behavior_zoomEventTarget = d3.event.target;
      d3_behavior_zoomTarget = this;
      d3_behavior_zoomArguments = arguments;
    }
  
    function mousedown() {
      start.apply(this, arguments);
      d3_behavior_zoomPanning = d3_behavior_zoomLocation(d3.svg.mouse(d3_behavior_zoomTarget));
      d3_behavior_zoomMoved = false;
      d3.event.preventDefault();
      window.focus();
    }
  
    // store starting mouse location
    function mousewheel() {
      start.apply(this, arguments);
      if (!d3_behavior_zoomZooming) d3_behavior_zoomZooming = d3_behavior_zoomLocation(d3.svg.mouse(d3_behavior_zoomTarget));
      d3_behavior_zoomTo(d3_behavior_zoomDelta() + xyz[2], d3.svg.mouse(d3_behavior_zoomTarget), d3_behavior_zoomZooming);
    }
  
    function dblclick() {
      start.apply(this, arguments);
      var mouse = d3.svg.mouse(d3_behavior_zoomTarget);
      d3_behavior_zoomTo(d3.event.shiftKey ? Math.ceil(xyz[2] - 1) : Math.floor(xyz[2] + 1), mouse, d3_behavior_zoomLocation(mouse));
    }
  
    // doubletap detection
    function touchstart() {
      start.apply(this, arguments);
      var touches = d3_behavior_zoomTouchup(),
          touch,
          now = Date.now();
      if ((touches.length === 1) && (now - d3_behavior_zoomLast < 300)) {
        d3_behavior_zoomTo(1 + Math.floor(xyz[2]), touch = touches[0], d3_behavior_zoomLocations[touch.identifier]);
      }
      d3_behavior_zoomLast = now;
    }
  
    zoom.on = function(type, listener) {
      event[type].add(listener);
      return zoom;
    };
  
    return zoom;
  };
  
  var d3_behavior_zoomDiv,
      d3_behavior_zoomPanning,
      d3_behavior_zoomZooming,
      d3_behavior_zoomLocations = {}, // identifier -> location
      d3_behavior_zoomLast = 0,
      d3_behavior_zoomXyz,
      d3_behavior_zoomDispatch,
      d3_behavior_zoomEventTarget,
      d3_behavior_zoomTarget,
      d3_behavior_zoomArguments,
      d3_behavior_zoomMoved,
      d3_behavior_zoomStopClick;
  
  function d3_behavior_zoomLocation(point) {
    return [
      point[0] - d3_behavior_zoomXyz[0],
      point[1] - d3_behavior_zoomXyz[1],
      d3_behavior_zoomXyz[2]
    ];
  }
  
  // detect the pixels that would be scrolled by this wheel event
  function d3_behavior_zoomDelta() {
  
    // mousewheel events are totally broken!
    // https://bugs.webkit.org/show_bug.cgi?id=40441
    // not only that, but Chrome and Safari differ in re. to acceleration!
    if (!d3_behavior_zoomDiv) {
      d3_behavior_zoomDiv = d3.select("body").append("div")
          .style("visibility", "hidden")
          .style("top", 0)
          .style("height", 0)
          .style("width", 0)
          .style("overflow-y", "scroll")
        .append("div")
          .style("height", "2000px")
        .node().parentNode;
    }
  
    var e = d3.event, delta;
    try {
      d3_behavior_zoomDiv.scrollTop = 1000;
      d3_behavior_zoomDiv.dispatchEvent(e);
      delta = 1000 - d3_behavior_zoomDiv.scrollTop;
    } catch (error) {
      delta = e.wheelDelta || (-e.detail * 5);
    }
  
    return delta * .005;
  }
  
  // Note: Since we don't rotate, it's possible for the touches to become
  // slightly detached from their original positions. Thus, we recompute the
  // touch points on touchend as well as touchstart!
  function d3_behavior_zoomTouchup() {
    var touches = d3.svg.touches(d3_behavior_zoomTarget),
        i = -1,
        n = touches.length,
        touch;
    while (++i < n) d3_behavior_zoomLocations[(touch = touches[i]).identifier] = d3_behavior_zoomLocation(touch);
    return touches;
  }
  
  function d3_behavior_zoomTouchmove() {
    var touches = d3.svg.touches(d3_behavior_zoomTarget);
    switch (touches.length) {
  
      // single-touch pan
      case 1: {
        var touch = touches[0];
        d3_behavior_zoomTo(d3_behavior_zoomXyz[2], touch, d3_behavior_zoomLocations[touch.identifier]);
        break;
      }
  
      // double-touch pan + zoom
      case 2: {
        var p0 = touches[0],
            p1 = touches[1],
            p2 = [(p0[0] + p1[0]) / 2, (p0[1] + p1[1]) / 2],
            l0 = d3_behavior_zoomLocations[p0.identifier],
            l1 = d3_behavior_zoomLocations[p1.identifier],
            l2 = [(l0[0] + l1[0]) / 2, (l0[1] + l1[1]) / 2, l0[2]];
        d3_behavior_zoomTo(Math.log(d3.event.scale) / Math.LN2 + l0[2], p2, l2);
        break;
      }
    }
  }
  
  function d3_behavior_zoomMousemove() {
    d3_behavior_zoomZooming = null;
    if (d3_behavior_zoomPanning) {
      d3_behavior_zoomMoved = true;
      d3_behavior_zoomTo(d3_behavior_zoomXyz[2], d3.svg.mouse(d3_behavior_zoomTarget), d3_behavior_zoomPanning);
    }
  }
  
  function d3_behavior_zoomMouseup() {
    if (d3_behavior_zoomPanning) {
      if (d3_behavior_zoomMoved && d3_behavior_zoomEventTarget === d3.event.target) {
        d3_behavior_zoomStopClick = true;
      }
      d3_behavior_zoomMousemove();
      d3_behavior_zoomPanning = null;
    }
  }
  
  function d3_behavior_zoomClick() {
    if (d3_behavior_zoomStopClick && d3_behavior_zoomEventTarget === d3.event.target) {
      d3.event.stopPropagation();
      d3.event.preventDefault();
      d3_behavior_zoomStopClick = false;
      d3_behavior_zoomEventTarget = null;
    }
  }
  
  function d3_behavior_zoomTo(z, x0, x1) {
    var K = Math.pow(2, (d3_behavior_zoomXyz[2] = z) - x1[2]),
        x = d3_behavior_zoomXyz[0] = x0[0] - K * x1[0],
        y = d3_behavior_zoomXyz[1] = x0[1] - K * x1[1],
        o = d3.event, // Events can be reentrant (e.g., focus).
        k = Math.pow(2, z);
  
    d3.event = {
      scale: k,
      translate: [x, y],
      transform: function(sx, sy) {
        if (sx) transform(sx, x);
        if (sy) transform(sy, y);
      }
    };
  
    function transform(scale, o) {
      var domain = scale.__domain || (scale.__domain = scale.domain()),
          range = scale.range().map(function(v) { return (v - o) / k; });
      scale.domain(domain).domain(range.map(scale.invert));
    }
  
    try {
      d3_behavior_zoomDispatch.apply(d3_behavior_zoomTarget, d3_behavior_zoomArguments);
    } finally {
      d3.event = o;
    }
  
    o.preventDefault();
  }
  })();
  